Snow Physics, cont.

After a wonderful spell of blessed warmth, we are again in the grips of the demon snow. Here is another reason why I hate snow. Walking dogs in snow is a task best left to the experts. Even on a flat, horizontal surface, the danger of slipping is large, but when you have to dodge cars that have blocked the sidewalk, this puts an extra measure of danger into the situation. You must now walk on the sloping driveways and this is a three-way problem, from a physics standpoint.

1. Snow and ice have a lower coefficient of friction with shoes than does cement, brick or asphalt. The coefficient of friction can be thought of as a way of telling how large a frictional force will be encountered when one object is in contact with another. A lower coefficient of friction, means less frictional resistance. When you walk, the static friction is greater than your force applied against the sidewalk, so you don’t slide. With snow and ice, however, you meet far less resistance and it is more likely that friction won’t be able to keep you in place.




2. When you walk across a flat, horizontal surface none of your weight is directed in the direction of your motion. Your weight points towards the center of the earth and you are moving forward. On an in incline, however, that changes. Even though the direction of your weight does not change, the angle of the surface has and it sets up a situation where a component of your weight is directed downwards along the slope. Without trying, you have now set up a force that is pulling you down the slope. The steeper the slope, the greater the proportion of your weight that is acting to pull you down the incline.




3. Your center of gravity is positioned roughly in the middle of your gut. As long as that point stays above your base of support (the area bounded by your feet), you stay upright. If that center of gravity finds itself away from your base of support, you fall. Walking on a flat surface, your center of gravity stays happily above your feet, on an incline, the chance is greater that your support base will get away from your center of gravity (your body leans out away from your feet). This makes your position very unstable.

Taken in sum, all of this means that I had to endure the indignity of landing at the bottom of a neighbor’s driveway, backside down, with two dogs licking my face to make sure that I was still alive to fill their food bowl. Happy New Year….

Have a Great Vacation

However you choose to spend the holiday season - enjoy yourself!

Here are some songs to add to your holiday repertoire - Physics Carols!

The End is in Sight

Vacation is almost at hand and we can at least count on the fact that there will be plenty of snow. Like everyone else, I would have liked a delayed start this morning, but we made do nicely. Physics - the exam is over and we will dip our toes into Chapter 8 tomorrow. Honors Physics - equilibrium problems can be a bear. Make sure to carefully write out the relationships for the 1st and 2nd conditions of equilibrium, take close note of the direction of each force and torque and choose an axis of rotation for the net torque evaluation that eliminates one of the unknown forces from the equation. We'll go over the problems in class tomorrow and pick up with more rotational dynamics when we return. Physical Science - tomorrow's lab will center around pulleys. This will give us one lab for the lever family and one lab for the inclined plane family for this unit. After vacation, we will add energy to our study of work, power and machines.

Snow

All of you who say you love the snow are crazy. Plain and simply crazy. However, here is a good site about snowflakes and snow crystals that even includes a good bit of physics...

SnowCrystals.com

Here is a site with a collections of cartoons about snow...

Off the Mark

And this is just a waste of good coffee...

Lots of Stuff Whirling

Centripetal force and torque were the two lab topics today. Physics - complete your centripetal force lab tonight - all graphs and calculations - so that we can discuss it tomorrow. Also, make sure that you have finished your review worksheet so that we can use that to prepare for Friday's exam. Honors Physics - make sure all calculations for the torque and equilibrium lab are completed. We will discuss torque in detail tomorrow and consider examples where applied force and the lever arm are not perpendicular. Then, we begin to examine the concept of rotational dynamics and evaluate, mathematically, the two conditions of equilibrium. Physical Science started their discussion of simple machines with the lever family and tomorrow's lab will center around levers. Our next long block, we will do a lab examining pulleys. This website has a nice flash lesson on simple machines and mechanical advantage.

Get the Office Together

Let me inform you of something - putting together a tv stand, office chair and desk with the enthusiastic help of two dogs is somewhat of a trial. Fortunately, they chose not to assist with the unpacking and setting up of the flatscreen. Home office with HDTV and Xbox 360 - I'm not sure if productivity will he high, but at least work will be fun.

Physical Science - inclined planes are an example of a simple machine, something that makes work easier. Notice that the amount of force you used decreased, but work increased by using the inclined plane. Mechanical advantage varied with slope angle, but efficiency was pitiful each time. Exactly as I would expect. Tomorrow, we will go into depth about machines and their connection to work and will stay with this topic a few days, with an additional simple machine lab to reinforce the ideas.

Physics - gravity and its effects on motion was the topic of the day. Tomorrow, some math practice with gravity and centripetal force problems and then a centripetal force lab on Wednesday. Thursday, review - Friday, exam. Week over.

Honors Physics - tonight's reading on torque will give you some background for tomorrow's lab. The lab will center on torque, balance and the two conditions of equilibrium. Pay attention to the sign conventions for torque, as you did for rotation, when working torque problems and analyzing the data in lab.

Flying Pigs!

Honors Physics investigated circular motion using a flying pig today and a fun time was had by all (except the pig who had to fly in a circle all day). Centripetal force is not always the tension in a cord, as for the last lab, it might be a component of that tension and you have to use vector analysis to puzzle that out. Tomorrow - review. Monday - exam.

Physics started defining the descriptors of angular motion and will take it further tomorrow. If you have used radians before, then this is nothing new for you. If you haven't covered that unit in math yet, we are not going to go in any deeper than we did today in class.

Physical Science - as you work on the Work worksheet (!), remember to keep track of the direction of force. Not always is weight the force you want for calculating work. Read the problems closely and consider direction of motion and direction of forces. Note: the answer for the last problem on the worksheet should really be a negative value, although the answer key lists it as positive. From our discussion of positive and negative work, you should be able to tell me why work, for this situation, is negative.

Busy, Busy, Busy

And I mean me, not you, so I've gotten behind posting. Oh well, life goes on...

Physical Science - tomorrow starts a new unit: Work and Energy. Both will still use the ideas that we have been building concerning motion and forces, we'll just add some new concepts to the pot and work towards tying things together into a tighter package. Physics - you guys start rotational motion tomorrow. We will not explore the mathematical aspects as much as the conceptual aspects, so do not worked up seeing all of the formulas in the chapter. Honors Physics - finished up talking about basic circular motion today and with an additional lab tomorrow and review on Friday, we are now in test preparation mode. The next chapter will examine interesting applications of circular motion that many of you engineers will appreciate.

Whirling Stoppers

Honors Physics investigated centripetal motion and how centripetal force and radius affect tangential velocity. Most groups seemed to show the appropriate patterns - with greater force (radius constant), tangential veloticy increases and greater radius (force constant)tangential velocity again increases. Think about those relationships when reflecting on the types of forces that can act as centripetal forces - gravity, friction, tension, etc.

Physics reviewed perfectly inelastic collsions and began work on elastic collisions. We will review this tomorrow and any other material that people request in preparation for Wednesday's exam.

Physical Science reviewed forces and fluids. Do not let go of your basic math skills. There is nothing in these problems that goes beyond the basic middle school math frameworks. Read the problem, identify what you are given for information, choose a formula or series of formulas to use that information to determine the final desired quantity. Although I give you the formulas on exams, as does the MCAS, you need to know how, when and why to use them. Tomorrow, we discuss Bernoulli's principle and the exam is on Wednesday.

Friday!

A few classes were low on students due to the band/chorus hoohah, but we made do nonetheless. Physics discussed yesterday's lab and used it to introduce the concept of collisions. Remember that both perfectly inelastic and elastic collisions demonstrate conservation of momentum and the same problem-solving skills apply. Only elastic collisions demonstrate kinetic energy conservation; however, inelastic collisions demonstrate a loss of kinetic energy. Physical Science students spent the period working on problems dealing with buoyancy and pressure. I posted the solutions on the course webpage for your two worksheet sets. Honors Physics discussed tangential velocity/acceleration and their connections to their angular counterparts. Centripetal acceleration was introduced and Monday's lab will allow you to investigate centripetal force and the resulting effects on motion. Have a good weekend!

Covering New Ground

Honors Physics had a test today and the homework assignment that drops you into the wonderful world of radians. For some of you, the the initial discussion of the unit circle and the relationship between radians and degrees will be a review. For others, this may be new - regardless, you will be using radian values for angle measurements and for then reporting values describing angular motion. Note: when you look through this and the following chapter, you may feel overwhelmed by what seem to be a whole suite of new formulas. Relax. You've seen them before, only wearing their translational cape. Pick each formula in Chapters and 8 apart and you find that it is the same as one we've used before, only with the angular equivalents of the variables. Here's a little video about the Unit Circle, for those who might need a review:



Physical Science - remember that forces are still the only things that can cause changes in motion, so when you discuss floating and sinking, discuss it in terms of the object's weight and the buoyant force of the fluid. Today's density discussion described that property of matter and your homework problems will give you some practice calculating density. However, density does not make something float or sink - density determines the objects weight for its size and the buoyant force of the fluid for the displaced volume. Regardless, it all comes back to forces and we'll tie these ideas together tightly tomorrow. For you, here's a video about density and buoyancy:



Physics - tomorrow's lab will have you review the concept fo 2-dimensional motion and vectors and use them to analyze momentum. It is easy to forget that momentum is a vector quantity when all the collision we study occur in one dimension. Refresh your mind about horizontal projectile motion, as that is what will occur after the collision in lab takes place and how to add vectors to find the resultant.

Still on Forces

Regardless of the specific concept we've attacked so far, forces have been lurking in the background. Welcome to the wonderful world of matter. Physics, today, discussed momentum and impulse, which branch from and look back towards our discussions of Newton's laws of motion. Tomorrow, we begin looking at conservation of momentum, which is a consequence of, specifically, Newton's third law of motion. Physical Science examined buoyant forces in lab. A couple of groups had slightly quriky results, but other groups work nicely demonstrated that the apparent lost of weight of an object (the buoyant force) was equal to the weight of the displaced water. The homework questions should be approached in terms of the forces involved. We'll add the ideas of floating, sinking and density to the mix tomorrow. Honors Physics prepared for tomorrow's exam. Even though I make light of it, do make sure that as we move into the next chapters that you remember to do your work with your calculators in radian mode. Every year, people get very frustrated that they aren't getting their homework problems right and it turns out they are working things in degrees.

Talent Showcase

Nate B. is a great woodworker and made these bottle/decanter stoppers:



The work is just lovely and he has other styles and types of wood. These would make very good holiday gifts; however, I am keeping mine for myself...

Different Places

Every course is working on something different right now, so things are pretty busy. Physics - the lab today on momentum and impulse, helped demonstrate the concpets that A block discussed on Wednesday and that E block will discuss tomorrow. Due to the less-than-frictionless lab situation, don't expect your impulse and momentum change values to be dead-on exact. They should be reasonably close, though, and we'll discuss the ranges of people's data tomorrow.

Honors Physics - tidied up the remnants of the momentum chapter. Exam on Wednesday. Bring questions for tomorrow's review and today's chapter review problems to discuss.

Physical Science - An overview and a couple of demonstrations of buoyancy. Tomorrow's lab will highlight those ideas and add in the concepts of calculating buoyant forces (rather than measuring them) and predicting floating and sinking for an object placed in a fluid. Even though water will act as our fluid in tomorrow's lab, the concept of buoyancy, buoyant forces and Archimedes Principle apply to all liquids and gases.

General Note: Some groups are getting a little careless in lab, in terms of equipment. First off, keep an eye on all the pieces for your sensors. Already, a couple of force sensors have lost their thumbscrews. Secondly, only put the sensors, LabPros and cables in the containers. I should not find heavy masses, string, scissors, etc. in there. Lastly - CLEAN UP WHEN YOU'RE FINISHED!!! Some groups do a great job with clean up and others do a terrible job. I am goign to have to start holding groups after class to clean up their stations if you can't take the initiative on your own. Repack materials, throw away trash (in the trash can, not the sink or lab drawers), return materials you borrowed from other groups to them, etc. Saves time for me and groups using the equipment after you.

Pet Peeve

After spending the afternoon refreshing myself on the Hellblazer graphic novels, I got in the mood to watch the movie Constantine, which is loosely based on that comic series. This brings me to one of my pet peeves: television shows and movies should not mess with the appearance of characters described in literary vehicles. Take this situation for example. Here's how John Constantine is supposed to look, according to the original source documents, the comics in which he is featured:



He was modeled after Sting, for pete's sake. Now, here's how he looks in the movie:



Keanu Reeves does not look like Sting. Further, the comic version wears a brown trenchcoat and is English. The movie version wears a black trenchcoat and is American.

I actually like the movie, mind you, and like KR's performance in the film, but someone like James Marsters (Spike from Buffy the Vampire Slayer) would have been a better physical fit for the role and he does a mean British accent. But what do they have him doing? Making audiobooks for the Harry Dresden novels. Dresden is 6 1/2 feet tall and dark-haired. Although I can't see Marsters while he is reading the book, just knowing he is average height and peroxide blonde is enough to make me simmer. they do have the vampire connection - Marsters played one on TV and Harry's brother is a vampire, but it is simply not enough. It is anarchy, I tell you. Pure anarchy...

Break Time!

Yeah! Hope everyone enjoys the few days off!

This was a very abbreviated week that found the Honors Physics folks completing the basic information in the Momentum and Collisions chapter, the Physics students starting this chapter and Physical Science folks starting to examine the action of forces in fluids. Honors Physics - by Monday, everyone should have completed through Practice 6G and C block will have completed #59 in the chapter review. Make sure that you can distinguish elastic from perfectly elastic collisions in terms of conservation of kinetic energy and mathematically analyze each type of collision. Physics - A block got a lecture on momentum and impulse today that E block will get next Tuesday. Monday is lab day, which will be devoted to examining the relationship between impulse and change of momentum. Physical Science got started with examining forces in fluids by discussing pressure, hydraulics and Pascal's principle. Have that worksheet completed by Monday so we can review the work in class.



As the holidays approach, people start looking for nice things to do for folks. Child's Play is a good charity that services children's hospitals. ALL of the monies and goods go to the children, none is retained for the charity itself and that is a rarity. Donations can be made through PayPal, or through Amazon.com. Hospitals set up Amazon wish lists and purchased merchandise is sent directly to the hospital. Children's Hospital in Boston is one of the hospitals serviced by the charity. The very cool thing is that Child's Play is a charity that has as its main source of donations the videogamer community. So, if you game, here's a way to do something to help out the gamer image and help sick kids in the process. Visit the Child's Play website for more information or to donate.

Have a great Thanksgiving!

Momentum

Today, although Physics completed their coverage of work and power, was a day devoted to momentum. Physcial Science - Now that we've gone over the conservation of momentum problems, take time to review them both on their own and in light of Newton's 3rd law of motion. Remember that impulse ties the two concepts together, to work to put the whole picture together in your head. Here are a are a couple of pages of lines to additional information about Newton's 3rd law and momentum:

Newton's 3rd Law of Motion - Action and Reaction

Momentum

Honors Physics is on the same page, as the lab today centered around impulse and momentum. Note that the elasticity of the rubber band or bungee a decent difference in the rate of momentum change (force). If you haven't watched the video about Spiderman and Gwen Stacy that I posted a few days ago, now is a good time to give it a look over.

Physics - Time today for reviewing power and initiating a general review of the chapter's material in preparation for Tuesday's test. Note: a number of folks are starting to lose their focus in class and not use class time productively. Also, the submission of homework is beginning to drop. Don't allow yourself to fall into bad habits. Your grades for remaining quarters are used by colleges for grants and financial aid and you still have to get teacher recommendations. It's not over until its finally over, so don't shoot yourself in the foot by forgetting that senior year doesn't end for months.

The Truth Comes Out

Finally, the reason the machines got the upper hand in The Matrix. I always suspected...

Half-Day

Well, at least for you guys. Physics had both sections meet today and we reviewed our lab unit in light of conservation of energy. We'll add on the rate of energy/work performed tomorrow - power. Exam will be Tuesday, so start reviewing the material in preparation. Physical Science - did't see you guys. Honors Physics - G block sat through a lecture on momentum and impulse. C Block will get the lecture tomorrow. The lab on Friday will target impulse and its affect on the motion of an object. Ciao for now...

Energy Abounds

Momentum and work were the subjects of the day and both involve the energy state of an object. Momentum and impulse deal with energy of motion (kinetic energy)and change in this energy when forces are applied. Work and energy are kissing cousins - reported with the same unit.

Physical Science - a discussion of yesterday's lab and a review of the momentum problems homework helped solidify the basic concept of momentum. Tonight's work adds the definition and consequences of impulse to the overall picture. The answers to those problems are on the course website and remember to show your work for full credit. Physics - groups finished the energy labs and tomorrow will be debriefing day. We'll discuss the results and how they apply to the topics being examined in this unit. Honors Physics - test day for you. Tomorrow, only G block meets and we'll be introducing momentum and the momentum-impulse concept. C Block will catch up on Thursday. Your lab on Friday will investigate the concept of impulse in assiciation wiht a single moving object.

Back to Work

Weekends are always too short and Mondays are always too long. At least most of you were engaged in lab activities. Honors Physics - make ready for tomorrow's exam! Its long block, so you should have plenty of time, but be ready to use that time efficiently. I added more non-multiple choice problems this go around. Gives you a bit more opportunity for partial credit. Regardless, momentum starts right on the heels of the exam.Physics began, and some completed, the elastic potential energy lab. Tomorrow we will finish the lab discuss the whole lab unit from the perspective on conservation of mechanical energy. Physical Science investigated momentum. Technically, you were examining collisions and how they demonstrate conservation of momentum, but we'll bring that piece into the picture after we have basic momentum a bit tighter under the belts. But, it was fairly clear that if you give an object with a fixed mass more velocity, you give it more momentum. The target moved further with the increasing momentum of the cart. Later, I'll show you how to use a bit of math to model the situation But, in the meantime, here's a good video that touches on momentum, impulse and conservation of momentum (and Spiderman, which is always acceptable).

Grade Day!

For some of you, grade day is a wonderful thing. For some of you, it is a day to try and find a hiding place for your report card. Things to remember:

1. Teachers don't "give" grades. We report grades that you earn, for good or ill. We give your average to the school and they assign a letter grade based on the accepted school grading scale.



2. Your grade may be the same as, better than or worse than your progress grade based on what you did during the last half of the quarter. Everything from the first day of the quarter goes into calculating your quarter average. And every quarter's average goes into calculating your final grade for the course.



3. Don't focus on one aspect of your work as being the source of your whole grade- your average takes into account everything you've done. Great homework scores don't erase poor test scores and vice versa. If the teacher took the time to assign and grade the work, no matter how small the assignment, it counts towards your average.



4. Missing work is a zero in a gradebook. Every homework, lab, or other assignment that you don't turn in you get zero credit. You are not simply scored on the work that you submit. Late work, of course, also hurts your grade.

So, use this quarter's grade to plan your course of action for next quarter. Were your test grades low - study more and get extra help. Not doing homework - get your rear in gear and do the job. Forgetting to turn things in - pay attention. The teacher calling for an assignment and other students getting their work together and passing it forward should be a clue that something is being handed in to be graded. Do what it takes to keep your current mark or bring it up to a higher level. It is all up to you, so start making a gameplan now...

Force and Energy

Physical Science pondered Newton's 3rd Law of Motion and started ruminating on momentum. Tomorrow, we will discuss the section review questions and you will begin to work a series of problems concerning momentum and impulse. On Monday, you will investigate momentum and its conservation in lab through the study of collisions (settle down, one object bumping another qualifies as a collision - no crunching of metal required). Phyics students discussed the last form of mechanical energy in this chapter - elastic potential. You guys seem to have a good handle on kinetic and gravitational potential, so the addition of this third form to your toolbag should be simple. The lab unit into which we move tomorrow will examine all three and the idea of conservation of mechanical energy. Honors Physics - today's lab permitted insight into energy conservation from the perspective of simple harmonic motion. Groups were able to calculate the spring constant for their spring and demonstrated that an object in SHM exhibit conservation of mechanical energy. Tomorrow, we will go over the lab, tie up loose ends concerning energy conservation and introduce the idea of power. Monday, complete our discussion of power and engage in a general review. Tuesday - exam. YeeHah...

And We Return

A nice Veteran's Day off and then back to work. For Physical Science, the day was spent engaged in an examination of action/reaction forces. Your graphs nicely demonstrated that with interacting objects, forces are simultaneously and mutually generated that are equal in magnitude and opposite in direction. Even if one of the objects in the system was inanimate - like the lab bench or a chair. Using a rubber band didn't change the pattern either. Also, a reminder that this not an example of balanced forces. Balanced forces are two equal and opposite forces acting on ONE object. Action/reaction forces act on TWO DIFFERENT objects. We will discuss this more fully tomorrow and introduce a new concept - momentum.

Physics further explored the concept of work by adding in its tie to energy. Kinetic and gravitational potential energy were discussed and, tomorrow, we'll add elastic potential energy. Remember that kinetic energy is associated with active work, while the potential energies are waiting to do work or represent work done on an object where the energy was stored. The lab unit into which we'll move on Friday will study all three of these energies and the idea of energy conservation.

Honors Physics - Conservation of mechanical energy was the topic of the day, which will be explored in tomorrow's lab activity. Remember to read ahead about simple harmonic motion and Hooke's law, along with the lab activity, before tomorrow. It will facilitate the analysis of the lab data quite a bit if certain aspects of SHM are already in the brain. Some, we discussed today with our example of a pendulum and energy conversions, so keep that in mind also. The test is on the calendar for next Tuesday.

Physics LOLdog pic for today:

Project Hint

Pssssstttt...Physical Science folks....here's a little video that might help you analyze the data you collect for your garden hose projectile motion experiment. Think about what the video is showing you and the physical reasons behind these patterns. Consider time in the air, vector components of the motion (vertical vs. horizontal), vector components of displacement (horizontal vs. vertical), etc. How does your data match up? Assume, as for your data, that the initial velocity is equal for each trial (launch angle).

Wii-ducation

I admit that the CPS response pads do resemble the Wii controllers and it seemed as if the Physics kids were playing a video game during lecture. It was good on my part to get an idea of how well folks were keeping up with the material while it was being delivered. Maybe Mrs. Allbach will let us use it again someday soon. Honors Physics got a chance to go over the kinetic-potential energy lab and get an earful of information about elastic potential energy, another enegy of postion (like GPE). Our next lab will focus on this type of stored energy and provide a further investigation of the conservation of mechanical energy. Physical Science - don't put off writing up the projectile motion experiment until the last moment. Even a brief coverage has to include all sections that I specified at the onset of the assignment and should be well-written, comprehensive, neat and something you'd be proud to turn in for a grade. Test scores were pretty good - some folks are going to notice a significant improvement over the last quiz. Nice job!

Yo Way Yo

Ok...so I spent the day watching the four movies that make up the first "series" of Lexx - I Worship His Shadow, Super Nova, Eating Pattern and Giga Shadow. It has been a while since I've watched Lexx and I could hear the call of the Brunnen G echoing in my head all weekend. Great scifi show - sort of like Farscape, but it aired a couple of years before Farscape. And an eclectic assortment of guest stars (at least for series 1) - Barry Bostwick, Tim Curry, Rutger Hauer and Malcolm McDowell (did you know he is the uncle of the guy who played Dr. Bashir on Star Trek: Deep Space Nine?). So, today was a write-off.

Hopefully you guys did better. Physical Science - noses should be ground down from being kept on the grindstone. Know the material well and work efficiently. Physics - you'll be getting an introduction to work and energy and a chance to use th CPS system. I've used it with the Physical Science kids before as a stand-alone, but this time finds it melded with out usual PowerPoint lectures. There will be slides tomorrow that you won't see in your packets because they are "question" slides. Don't let that confuse you as you follow along in the packet. Honors Physics - we'll go over the energy lab and use it to clarify ideas about work. Think about what we went over for our work discussion and see how, and if, it applies to the patterns that you observed in lab. Did velocity increase when gravity did positive work? Did it decrease when gravity did negative work? Did position change when work was done on the ball? Etc... Well, back to Lexx.

"Yo Way Yo
Home Va Ya Ray.
Yo Way Rah.
Jerhume Brunnen-G!"


check out the mp3...
Kai would be proud

Moons

The full moon of each month has a name. November is the Beaver Moon - go figure...

• January: Wolf Moon

• February: Snow Moon

• March: Worm Moon

• April: Pink Moon

• May: Flower Moon

• June: Strawberry Moon

• July: Buck Moon

• August: Sturgeon Moon

• September: Harvest Moon

• October: Hunter's Moon

• November: Beaver Moon

• December: Cold Moon

Friday!

Everyone has been waiting for today, and it finally arrived. Physics students had to endure an exam, but get to play with some fun technology on Monday. Although we won't be doing a lab, we will be using Mrs. Allbach's CPS system during lecture. Think of it as having a remote control in your hand to send answers directly to my computer. Physical Science students reviewed for their exam and Honors Physics conducted a lab activity comparing the kinetic and potential energy of a tossed ball. That's all you need to know...

Well, at least its not snow...

Too much rain today, but at least it will, hopefully, strip the last leaves from the trees. I am tired of raking...

Physics - today's review touched on all topics that are likely on tomorrow's exam. Don't forget your calculators and, A block, don't forget to have today's homework assignment ready to hand in at the beginning of class.

Honors Physics - the energetic world of energy. In physics, we don't much past kinetic, gravitational potential, elastic potential and electric potential energies, but there are many more in the energy pantheon. Tomorrow's lab will target KE and GPE and the conversion between the two. We will do a lab later this unit for elastic potential energy and the determination of the spring constant using Hooke's law. Read over the lab tonight and have Practice 5D and the Section Review ready for Monday.

Physical Science - terminal velocity graphs looked very good and did match the model that I would predict for your data collection situation (-cv2). Heavier objects do fall faster than light objects because their terminal velocity is larger. Your TV for each additional filter produced a larger terminal velocity than the previous trial. Take air resistance out of the picture and they would all fall with the same acceleration. We will discuss the lab tomorrow and remember to bring questions about Monday's exam.

Back from Break

No school Tuesday and, now, back to the saltmine. And the mine was definitely salty...lots of things to do and lots of progress to make.

Physics - a discussion of the friction lab helped to frame the discussion of the lecture on air resistance. Tomorrow, bring the completed homework questions and any additional needs to prepare for Friday's exam. I'll have your labs back to you tomorrow to use for studying.

Physical Science - tidying up loose ends concerning gravity and its effects on motion. Projectile motion and orbital motion consider motion in two dimensions. You should be aware how those dimensions affect (or fail to affect) each other and describe the motion in qualitative (non-mathematical) terms. Tomorrow's law will allow you to investigate the role of air resistance in determining an object's motion. We'll discuss the lab on Friday and address any final questions about the forces unit. The exam Monday will cover the material through tomorrow's lab and reach back to our study of friction. Also, tomorrow, I'll give you a packet on how to write a lab report based on a student-created experiment (chapter review item #42). You should use that as a guideline for your write-up and we will go over it briefly tomorrow.

Honors Physics - Work can be described as a change in the energy of an object and tonight's homework looks at that aspect of the work concept. Note: although it is not stated in the problem, for 5C #3, assume that the car is sliding down the driveway - it is not being driven down the incline.

Short Week

No school tomorrow, so the week should just fly by!

Honors Physics - exam today on Chapter 4 should be graded by Wednesday, but (of course), we have to deal with the people who were absent and have to take a make-up test. Wednesday, we begin a study of work and energy, which will again tie into forces and the idea of net force.

Physics - make sure that you have completed the questions for your lab by tomorrow. We will discuss the lab in light of our lecture on friction. Thursday, general review of the chapter and Friday - EXAM!

Physical Science - it was interesting to read your essays on orbital motion. A number of your did a great job! A few helpful hints - when key words are given to include in your discussion, do not simply define the terms. Discuss how they act together to influence the topic. So, simply telling me what is inertia, gravity, free-fall, etc. is not sufficient. Tell me how they work together to produce orbital motion. Also, DO NOT copy your work from any source - that is plagarism. If I can find a website that has all or part of your essay or paper word for word, you are guilty of theft. Stealing someone's words is theft, just as if you stole their money and it is considered academic dishonesty. Read a variety of sources and synthesize the ideas, frame things in your own words, with your own analogies or examples. If you are used to simply copying and pasting material from the Internet into your papers, then you should be very aware that high-school teachers take this seriously and you do not want to be caught doing this when you submit something for a grade.

Thursday

Physics was engaged in examining friction and, despite a few whining complaints about the number of trials requried for the activity, all went well and good data is being collected. We will complete the data collection tomorrow in class. Physical Science - work on those basic math and calculator skills. Seriously. Some folks really need to just buckle down with a gazillion problems and spend time working them until they get them right. As stated early in the year, the mathematical techniques used for solving the problems at this level of physics are limited in number and we have pretty much covered all of them. And, they are nothing more advanced than anything in the middle-school math frameworks. So, grab the tiger by the tail and get that math nailed down. We simply do not have time to linger over material that should already be in your personal academic toolbox. We have to get the physics down in preparation for MCAS...Honors Physics - come ready with questions tomorrow in preparation for Monday's exam. We will go over today's homework problems and can go over any additional topics that need review.

Quick Post

Watching The Fifth Element on On Demand HD and am only going to break away my attention for a sec or two. Physics - be prepared by reading over that lab sheet and keep in mind our discussion of today when addressing the analysis questions. Honors Physics - the air resistance lab today went well. Considering the results in general and the drag force model that best fit your data specifically, be prepared to provide a good answer to the question of why heavier objects do hit the ground first when air resistance is present during their fall. Physical Science - complete that gravity worksheet and check your answers with the key that is on the class website. Bring questions with you tomorrow. Quiz on Friday covers friction from the last chapter and material in this chapter up to gravity and free-fall. Kudos to those who are coming in after school for extra help. Being in high school means taking charge of your own learning and asking for help when needed is a very important step. Ciao for now...

Busy Tuesday

Physics and Honors Physics stalwartly sat through lectures on forces - weight and normal for Physics and friction for Honors Physics. Problem-solving skills are emphasized in the homework assignments. Air resistance lab for Honors Physics tomorrow to examine a variation on the friction theme and Physics will take on static and kinetic friction in lab on Thursday. Honors Physics Chapter 4 exam falls next Monday and some folks in G block will lose a review day due to Peer Mentoring. Plan ahead!

Physical Science bustled around investigating free-fall acceleration and all groups completed their work. What I gathered from circulating around was that data collection went well and groups realized that (1) the accepted value for acceleration due to gravity is not a "magic number," but can be measured in the lab and (2)acceleration due to gravity is constant acceleration - it does not change with time or speed of descent. This allows its use in kinematics equations with confidence. BTW: here's what some of you looked like at the end of the period:

Another Week Begins

Physics did a nice job listening to me gab on about Newton's 2nd and 3rd Laws of Motion and correlate the previous few days labwork with the theory in the text. Tomorrow, we expand the idea of forces and motion into the area of specific forces - weight, normal and friction. We'll keep things fairly unidimensional, but will look over some 2-dimensional examples in class.

Physical Science started examining their first field force - gravity. Be able to work with the formula for Newton's Law of Universal Gravitation (yes, it is on the MCAS formula sheet) and understand the theory that is expressed by the formula. The lab tomorrow will examine acceleration due to gravity - make sure you have read over the lab by class time. We will discuss the homework from today on Wednesday, along with the lab, and tie together the ideas of weight and gravitational forces. Be ready for another math packet dealing with gravitational forces to be tossed at you in the near future.

Honors Physics completed the static and kinetic friction lab today. Some groups had to re-evaluate data and collect a few additional data points for the coefficient of friction piece, but things look pretty good as of now. We will discuss the lab results tomorrow and begin a discussion of frictional forces, their impact on motion and the meaning of that pesky coefficent of friction.

Sunday is for Soap

Made some soap for Halloween. Have to add some pumpkins to the group, though...

Pics of Saturday

A chickadee flock is moving through my neighborhood bringing chickadees, titmice and two new additions to the yard:

White-breasted Nuthatch



and Downy Woodpecker



Also, I had to build a Putt Putt boat for an online course in engineering that I am taking and it I finished it today. Tested it in the bathtub and, although ugly, it did putt around proudly:

Friday Fun

Physical Science did a good job with the N2 worksheets - Congrats! I also appreciate your assistance with beta-testing Mrs. Allbach's new eInstruction system. I'll try and steal it from her from time to time so that we can use it for some spot checks for understanding. Starting Monday, we bring gravity into the picture. We will examine it as a force and practice using the formula Newton devised to calculate the gravitational force between any two objects. Gravity also adds a component to motion of objects on Earth. Launch something horizontally and it also starts moving downward. We will take some time to talk about this type of motion - projectile motion with this unit. Yes, darts is an example of projectile motion...



Physics completed their lab activities for Newton's laws of motion. We will discuss these labs on Monday and use them to enhance our discussion of the basic concepts and illustrate problem-solving techniques. Graphs looked good - the only thing I noticed was that some of the N2 graph slopes were not as close to the object's actual mass as they should have been. Probably some drag from the cables. The N3 graphs were especially nice!

Honors Physics - most groups completed their data collection, but a few need to tidy up some loose ends. The completion will take place on Monday, when groups will also have time to brainstorm the Analysis questions. C block had a bit of funny data for the coefficient of friction piece of the lab. Remind me to take a closer look at that information on Monday.

Lab Day

Physics and Honors Physics both toiled in lab today investigating different aspects of forces. Physics did a lab that demonstrated the force/mass/accelerations discussed by Newton's 2nd law of motion.



Honors Physics took up the study of static and kinetic friction, which will be completed in class tomorrow. Lab work for both classes will be completed tomorrow and Monday will be the day to debrief this body of work.

Physical Science beat up their calculators working problems for Newton's 2nd Law of Motion and the connections with basic motion. The answers for these problems are online and we will address any difficulties tomorrow, along with furthering our discussion of forces.

As for where I get cat pics, such as the one for yesterday....Click Here

Click here for the same thing, but with dogs...

The Bugs Always Win

Those who had be during G-block know that I was descending into the head-on-desk-and-drooling stage of a cold, so I am home today trying to stop it from getting worse. I may or may not be able to talk tomorrow, but at least I won't be having fevered hallucinations that you are all Smurfs. Do you work, don't bother the sub and have a good day.

Forces, Motion and Newton

Physics folks got an earful about Newton's first law of motion and a review of free-body diagrams. Remember that the force producing an observed acceleration is the net external force - sum up those vectors! Tomorrow, you will get to preview N2 and N3 in lab and we will take up the concepts in class on Thursday. Read the lab packets tonight to get an idea of what equipment you will be using, data you will be collecting and how to make your group work efficiently.

Honors Physics - coverage today of weight and the normal force with time to work on homework after the laws of motion quiz. A nice, easy day. Admitedly, half the people weren't here due to the field trip, but that was just butter on the bread. Tomorrow, we will go over the homework while the field trip slackers take their quiz and then move on into friction. The concepts of weight, the normal force and their resolution will take on large roles as we beging to calculate frictional forces acting on objects.

Physical Science - an entry into Newtonville with an overview of the first of his 3 laws of motion. We will work more with his 2nd law of motion in class tomorrow, espeically with the math portion. For those who did not score well on the math portion of their last test, stop in before or after school tomorrow to go over those pieces. You will need those skills as we move forward through this unit and through the course.

Addendum: I am losing my voice again, so everyone be prepared to listen closely and help out neighbors with work. Laughing at me is permitted, but be prepared to dodge a flying eraser...

The Force is Physics

Everyone is on forces and a wonderful thing it is to behold. Honors Physics - quiz tomorrow on free-body diagrams and Newton's Laws of Motion. Expect about 15 questions, some theory and some math. Those of you who will be on the field trip will take the quiz on Wednesday. Physics - tomorrow finds us building on today's discussion of free-body diagrams and Newton's 1st law of motion. We will work through Newton's 2nd law of motion and then, on Wednesday, conduct lab investigations on both N2 and N3. Physical Science - good job on the friction lab today. Every group completed their work and the graphs produced showed me that the data collection went well. Now, can you pull together what the data actually means? Think hard about your own personal experiences with friction and study well your graph for static vs. kinetic friction. A re-read of your class notes should provide the explanation for the fact that your static friction values were greater than your kinetic friction valuesl We will discuss the lab tomorrow and start to develop our concept of how forces impact motion. A note on the motion exam - some folks did very well and congratulations to you!!! For others - remember that mathematics is a tool to use and physics uses math as a tool to reach a goal. You have to be able to think quantitatively, to apply math to situations. It is more than plug and chug and this will take practice for some of you. For the next exam, try to improve on your math performance and get help from me to make that improvement possible.

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Build your own Cylon Pumpkin! Cool, yet easy electronics work with slick results...Click here for full instructions.

Laws of Cat Physics

Law of Cat Inertia
A cat at rest will tend to remain at rest, unless acted upon by some outside force - such as the opening of cat food, or a nearby scurrying mouse.

Law of Cat Motion
A cat will move in a straight line, unless there is a really good reason to change direction.

Law of Cat Magnetism
All blue blazers and black sweaters attract cat hair in direct proportion to the darkness of the fabric.

Law of Cat Thermodynamics
Heat flows from a warmer to a cooler body, except in the case of a cat, in which case all heat flows to the cat.

Law of Cat Stretching
A cat will stretch to a distance proportional to the length of the nap just taken.

Law of Cat Sleeping
All cats must sleep with people whenever possible, in a position as uncomfortable for the people involved as is possible for the cat.

Law of Cat Elongation
A cat can make her body long enough to reach just about any counter top that has anything remotely interesting on it.

Law of Cat Acceleration
A cat will accelerate at a constant rate, until he gets good and ready to stop.

Law of Dinner Table Attendance
Cats must attend all meals when anything good is served.

Law of Rug Configuration
No rug may remain in its naturally flat state for very long.

Law of Obedience Resistance
A cat's resistance varies in proportion to a human's desire for her to do something.

First Law of Energy Conservation
Cats know that energy can neither be created nor destroyed and will, therefore, use as little energy as possible.

Second Law of Energy Conservation
Cats also know that energy can only be stored by a lot of napping.

Law of Refrigerator Observation
If a cat watches a refrigerator long enough, someone will come along and take out something good to eat.

Law of Electric Blanket Attraction
Turn on an electric blanket and a cat will jump into bed at the speed of light.

Law of Random Comfort Seeking
A cat will always seek, and usually take over, the most comfortable spot in any given room.

Law of Bag / Box Occupancy
All bags and boxes in a given room must contain a cat within the earliest possible nanosecond.

Law of Cat Embarrassment
A cat's irritation rises in direct proportion to her embarrassment times the amount of human laughter.

Law of Milk Consumption
A cat will drink his weight in milk, squared, just to show you he can.

Law of Furniture Replacement
A cat's desire to scratch furniture is directly proportional to the cost of the furniture.

Law of Cat Landing
A cat will always land in the softest place possible.

Law of Fluid Displacement
A cat immersed in milk will displace her own volume, minus the amount of milk consumed.

Law of Cat Disinterest
A cat's interest level will vary in inverse proportion to the amount of effort a human expends in trying to interest him.

Law of Pill Rejection
Any pill given to a cat has the potential energy to reach escape velocity.

Law of Cat Composition
A cat is composed of “Matter” plus “Anti-Matter” plus “It Doesn't Matter”.

Friday, Friday

...so good to me (or is that Monday, Monday?) Bungee jumping in Physics, tug of war in Honors Physics and the fun of friction in Physical Science. The bungee lab did a good job of demonstrating the changes in acceleration produced by forces. Free-fall with a slack elastic and an abrupt acceleration when the elastic applied its force on to the jumper. Very nice graphs and no bungee jumpers were harmed in the experiment. Newton's 3rd law of motion was so well demonstrated in Honors Physics lab that the graphs could have been framed. Perfect mirror images for the action/reaction forces regardless of whether they were applied through an elastic or non-elastic cord. Those who got to do the extension saw that the graph patterns could not have been produced by any action by a lab partner. Inanimate objects also produce forces and follow Newton's laws. Physical Science got a yap-fest about balanced/unbalanced forces and the specific force of friction. We are going to explore these concepts in Monday's lab and then launch into a more in-depth examination of the effects of forces on motion.

What a Day...

so much to do...Honors Physics did a bang-up job for the N2 lab. The force/acceleration graphs well presented the data and the slope values were quite close to the actual masses of the carts + sensors. Tomorrow's lab extends the idea of forces with a examination of action/reaction pairs. Read over the lab tonight and look over the extensions. Between tomorrow and Monday we will do the lab and a couple of the extensions, as well.

Physics - test scores varied, but averaged in the "C" range, which is nothing to sneeze at. For folks with particularly low scores, we can take some time go over things again and work on increasing your marks.

Physical Science - people, people, people...remember that part of the examination experience is the time factor. Work efficiently and study sufficiently that you are not having to ruminate over every item. Next time - when the bell rings, the test is OVER. Period. Tomorrow, we will begin our examination of forces, which will allow you to investigate how acceleration is actually promoted in objects. You will not be able to leave behind the concepts of motion - they are an integral part of this unit and more to follow, so sharpen your skills to the finest.

Make This You Can

Need to make some cheap holiday gifts...

Days of Review

With two exams tomorrow, 4 classes were engaged in review. Physical Science did a very good job asking questions and focusing in on areas in which they had difficulty. Physics, same good job so I am expecting fine performances on the tests.

Honors Physics - Newton's Laws get intense lab treatment over the next two days with N2 being investigated tomorrow and N3 following on Friday. As for N2, folks seemed to do well with the homework problems, with the exception of #24 of the Chapter Review. That one is a bit sneaky. I will wager that most of you are forgetting a force in your free-body diagrams and that is why your answers are much larger than the actual values. Hint: think about what would happen to the cart if the rope snapped and why. Now, quantifying that bit is a tad tricky, but it definitely can be done with the skills you currently possess. Later on, the technique will actually become old hat...

Late Post

but TV's good, so what the heck...

Honors Physics - equilibrium went well, so bully for you! The concept of net external force will haunt you throughout the year, so don't let the plain ol' "F" in a formula fool you into thinking that it means anything less than the vector sum of all forces acting in a situation. We've drawn free-body diagrams, used net force to establish conditions for equilibrium and today used net force to determine acceleration of an object. Tomorrow, the conclusion of Newton's 2nd law of motion and a discussion/demonstration of Newton's 3rd law of motion. Thursday, a lab examining Newton's 2nd law of motion from both the force and acceleration point of view using the Vernier system. Friday - a laws of motion quiz? The magic 8-ball says "possibly..."

Physics - the walk through of a projectile launched at an angle went well. Good analysis of the situation. Tomorrow, we will discuss the Chapter 3 review sheet and address any questions you have to prepare you for Thursday's exam.

Physical Science - kinematics equations require practice and make sure you use the formulas that I tell you to use. There is a reason that you are practicing with the MCAS formula sheet - THE MCAS EXAM! Work the problems again if you had difficulty and I can dig up more problems if you find the need. Tomorrow, you will get practice working with the concept of uniform circular motion and some review work in preparation for for Thursday's exam. Bring along any questions that you might have for motion. Then, its on to forces!

Just a Short Note

...so as not to disrupt the 4-day weekend you guys get to enjoy. Physical Science students - make sure to finish up any pieces of your lab and complete the kinematics problems using your MCAS formula sheet. The answers are on the website for you to check your work. Looking towards next Thursday for your Motion test. Physics - try not to soak your entire family doing the garden-hose activity. Have information and explanation pulled together so that we can discuss things on Tuesday. Your exam is scheduled for next Wednesday. Honors Physics - The solutions to the Chapter 4 worksheets are online so that you can check your work. Remember - you are still using the techniques for vector operations that you learned last chapter. There isn't really anything new - you are just applying them to forces. Have a good weekend!

Kinematics Formulas

Honors Physics - my oh my...what am I going to do with you? One of the main concepts for 2-dimensional motion is that each component can be analyzed independently and that the basic kinematics formulas apply. Also, there are no separate formulas for projectile motion - remember the formulas on your lab sheet? Same ol' ones we worked with last chapter and over and over and over and over again this chapter. When working problems on the board, all I've used is that same formulas set ad nauseum. So, if you were perplexed by the formula sheet (despite the fact that I said yesterday IN CLASS that the formula sheet you would get would be the one from the last chapter since those were the only ones you need), you need to go back and re-examine the basic idea of 2-dimensional analyses.

Physics - Good job today with horizontal projectiles. Tomorrow, we will work some additional problems and get more practice with vectors, if needed. The Chapter 3 exam is scheduled for next Wednesday, so we will wrap up all loose ends by Tuesday (remember that we lose Friday and Monday).

Physical Science - Lab data today from today looked good for those groups who were starting to graph out theirs. Tomorrow, data collection and analysis will be completed. I am looking towards next Thursday as the day for the motion exam. Forces, also included in Chapter 10 will not be part of this exam and will be addressed as a separate topic after the exam.

Hitting the Target

Physics folks outdid themselves in lab today. Precise measurements and calculations led to hitting of some tiny targets. Tomorrow, we will discuss the theory behind horizontal projectiles and get some more practice with the mathematics involved.

Honors Physics - predict a bit of everything on the exam tomorrow. I think the tally is 20 questions (Hah! Now, that's funny) and you'll get the formula sheet that has the kinematics formulas on it. Since those are the only ones you really need, that will suffice. I'll also toss in good ol' SOHCAHTOA on the board or something if you blank on those relationships. Don't forget to have 3E, 3F, 3.4 Section Review and the Chapter Review questions ready to hand in when you get to class.

Physical Science - Looked over the homework sheets and many people did well. A few could use more practice, and you can get more problems from me for extra work. Tomorrow, we will investigate acceleration down and inclined plane and how this acceleration can be influenced by angle. Hint: practice with the stopwatch before you begin taking data. They always give people difficulties when you first start to use them. Once you get the hang of how sensitive are the buttons, things will go smoothly.

You're on Your Own

I won't be in tomorrow, so you guys (1)listen to the substitute (2)do your work (3)leave the room in the condition you found it. Honors Physics - yes, the exam is still on Wednesday. See you Tuesday!

Friday's Findings

Physical Science had a lot of information thrown at them today. A review of vectors and then an overview of acceleration. Work well on the homework worksheets and we will go over them on Monday, when you will get problems dealing with the more complex formulas that you saw on the MCAS formulas sheet. Watch out for unit conversion issues on those worksheets and remember to report values with the proper unit and direction (if applicable). We will spend a good bit of time examining graphical and mathematical techniques to analyze and describe motion, so hold on to your hats!

Physics - Quiz scores varied, but work with projectiles will allow you to further practice those vector skills.

Honors Physics - take time and work hard on the additional projectile problems. We will go over them on Monday and engage in a discussion of relative motion. The exam is still scheduled for Wednesday.

Have a great weekend!

Vampire Vectors

Some of you in Physics left class looking like your blood had been drained by an unholy being. Yep, vectors can do that to you...Regardless, folks made a lot of progress with skills for drawing appropriate vector diagrams, understanding coordinate systems and vector combination. Tomorrow's quiz will be a few questions concerning the nature of vectors, basic vector addition, vector resolution and coping with non-perpendicular vectors. I think that there are 7 questions on the quiz (don't quote me, though, as I wrote it yesterday) and none will have 11 different vectors to work with (like today's activity).

Honors Physics folks also looked exsanguinated and, again, this was not a surprise. Projectiles launched at an angle make for tough analysis. The infuriating thing is that the math is not really hard and the basic concepts are not hard. But, putting it all together takes very sharp problem-solving skills and a good measure of creativity. Being willing to take a risk and start over if necessary is also a big help. The two problems that were assigned today are not simple, but they are fun, if you appreciate a challenge. We will discuss them tomorrow and perhaps allow some time for group brainstorming.

Physical Science - You guys got your feet wet in the Great Vector Ocean today and seemed to take to them fairly well. We will discuss today's worksheet in class tomorrow before embarking on a discussion of aceceleration (which is also a vector). There will be a good number of practice problems for acceleration and velocity to work on in class tomorrow, so have calculators at hand. Note: class average for the Mathematcs exam was 81.6%, which is quite respectable. Good job!

Tru Dat...

more music charts

Beyond this piece of wisdom, not much to add for today. Physics did a great job working with vectors - the challenge comes tomorrow! Physical Science - most students stayed awake during lecture, so I'll count that as a win. Have calculators tomorrow as we work problems concerning motion and the rate of motion. Honors Physics - Some very good shots today that nearly hit the target. Two groups per class missed the target by a mile, but strangely (1) had similar values for initial velocity and (2) sat at the same lab stations. Could be technical difficulties - I will investigate tomorrow. Be ready for 3E discussion tomorrow and for more practice with projectile motion. Gotta go...Ghost Hunters, House and Bones all on simultaneously. My sore remote control finger makes typing tough...

Following Through...

Physical Science - Haunted by the spectre of lab directions. Several times, again, I noticed groups not following directions for their lab activity. I should never find that you have skipped steps while working through a lab activity or have simply failed to follow what the directions tell you to do. Also, make sure that you pay close attention to the focus of the lab and of the information being collected/presented. I should not, for instance, have to point out axes labels on graphs displayed on the computer monitors. Work towards doing labs efficiently, but correctly. Spend your time on the analysis rather than trying ti figure out what to do when the procedure is written out on your lab sheet.

Physics - Many of you need to get with the following through, also. I looked through the lab sheets submitted today and noticed that a number of individuals just seemed to ignore the actual point of the lab - finding the acceleration due to gravity! Your graphs were hastily constructed and not set up to answer the question. It is good to collect the data, but the data is useless if meaning is not made of it. This time, I knocked a few points off these labs; next time, I will knock off many points. Tonight's homework will allow you to practice your vector resolution techniques. We will discuss this tomorrow and our next lab block will give you an opportunity to practice the vector techniques you have been studying so far in the chapter.

Honors Physics - Tomorrow's lab will require attention to detail, so make sure to read it carefully tonight. Think about all the concepts we discussed about horizontal projectiles as you perform the lab and complete the calculations. If time permits, we may be able to modify the procedure into a study of a projectile launched at an angle. This would facilitate your working through the homework problems. BTW: be willing to use up paper on these problems. They can be brain scratchers. Identify all known and implicit information. Sketch the situation. Break down initial velocity into its x- and y-components, consider the symmetry of the situation, think backwards (it can be a great help) and make use of substitutions to reduce the number of unknown variables.

2D Motion

Honors Physics - Our discussion today ended at with the motion of horizontally-launched projectiles. Remember: initial velocity in the x-direction is constant (a=0), initial velocity in the y-direction is 0, y-direction motion is free-fall, time depends on the y-direction motion and motion in the x- and y-directions is independent. Tomorrow, we examine projectiles launched at angle (initial velocity in both the x- and y-directions) and Wednesday's lab will concentrate on projectile motion. Keep those kinematics formulas from last chapter at the front of the brain and remember to think about vectors and their resolution as we move through this unit.

Physics - today's lab continued work with vectors, specificallty vector resolution - the breaking down of a vector into its x- and y-components. You were able to study acceleration in the vertical direction by looking at the motion of an object in 2 dimensions (cart on inclined plane). This is how we will approach motion that is 2-dimensional when we analyze it more fully tomorrow. Complete the lab tonight (don't forget to make the acceleration vs. sine of ramp angle graph) and we will discuss it in class tomorrow.

Physical Science - Most people scored well on today's exam and are definitely ready to move into our next unit (Motion). We will introduce this unit with a lab centering on the rate of motion (velocity) tomorrow in class and then begin our discussion of concepts that describe motion. If you are still having difficulty with the math concepts, I can give you addition practice problems or out-of-class help, but we do need to move on with the material for the course. There will be many opportunities to practice and demonstrate the basic math skills as we move through the physics topics this year.

Physics Jokes

1. A student riding in a train looks up and sees Einstein sitting next to him. Excited he asks, "Excuse me, professor. Does Boston stop at this train?"



2. Heisenberg went for a drive and got stopped by a traffic cop. The cop asked, "Do you know how fast you were going?" Heisenberg replied, "No, but I know where I am."



3. The answer to the problem was 'log(1+x)'. A student copied the answer from the good student next to him, but didn't want to make it obvious that he was cheating, so he changed the answer slightly, to 'timber(1+x)'



4. An experimental physicist performs an experiment involving two cats, and an inclined tin roof.
   
   The two cats are very nearly identical; same sex, age, weight, breed, eye and hair color.
   
   The physicist places both cats on the roof at the same height and lets them both go at the same time. One of the cats fall off the roof first so obviously there is some difference between the two cats.
   
   What is the difference?
   
   One cat has a greater µ.



5. Jupiter Scientific is pleased to report that physicists have embarked on their own product safety campaign, recommending that manufacturers provide consumers with all of the following labels:
   
   WARNING: Due to its heavy mass, this product warps the space surrounding it. No health hazards are yet known to be associated with effect.
   
   NOTE: This product may actually be nine-dimensional but, if this is the case, functionality is not affected by the extra six dimensions.
   
   HEALTH WARNING: This product (and every product of the Manufacturer) emits low-level nuclear radiation.
   
   NOTE: A subatomic "glue" holds the fundamental constituents of this product together. Since the exact nature of this glue is not yet fully understood, its adhesive power cannot be guaranteed. To date, no known malfunction of the product has resulted from glue failure.
   
   DISCLAIMER: Manufacturer is not responsible for loss should this product disappear into a wormhole.
   
   LIMITED WARRANTY: Despite the efforts of the Manufacturer, the chaos in this package has increased since being shipped. If such chaos has rendered the product defective, Buyer shall not hold Manufacturer responsible. Claims in this regard should be aimed directly at the Shipper.
   
   NOTE: Despite its appearance, this product is more than 99.99% empty space.
   
   READ THIS BEFORE OPENING: According to quantum theory, this product may collapse into another state if directly observed.
   
   HANDLE WITH CARE: This product contains countless, minute, electrically charged particles moving at extremely high speeds.
   
   EXTREME CAUTION: This product has an energy-equivalent that, if exploded, could destroy a small town. Under no circumstance shall a User perform a mass-energy transformation on any of the contents in this package. In case of misuse, liability shall rest entirely with the User.
   
   GUARANTEED RETURN CLAUSE: Because of the uncertainty principle, we have shipped this product with a limited speed notice. However, if shippers have disregarded our notice, we cannot guarantee that all the contents are in the box. If you discover missing components, please call the 1-800 number on the instruction sheet.
   
   IMPORTANT: This product is composed of 100% matter: It is the responsibility of the User to make sure that it does not come in contact with antimatter. Under no circumstances will the Manufacturer be liable for User mishandling in this regard.
   
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   AS REQUIRED BY LAW, we must inform you that any use of this product increases the amount of disorder in the universe. As of the date shipped, Congress has not passed any bills assigning a tax on disorder pollution.
   
   USE LIMITATION: This product cannot be guaranteed to function normally near a black hole.

Saturday with House

Since the USA network is having a House marathon, I have to be home for the duration. This means that I can catch up on yesterday's gossip information.

Honors Physics - C Block's lab data may be a little squiffy due to the plastic inclined planes. I think that slipping might affected the runs and were the reason for some of the unexpected peaks in the velocity/time graphs. G Block only had wooden planes and their runs were far cleaner. Memo to me: only use wooden inclined planes for this experiment next year. Even with the bumpy data for some groups, the data did provide an insight into the methodology Galileo used to understand and describe the idea of free fall. Admittedly, the values calculated in this experiment reflect the influence of friction. This does not negate the principle, we must simply account for the extra force influencing the motion of the cart.

Physics - Our discussion of the nature of vectors will give you a little taste of why Monday's lab with inclined planes can give a decent value for the acceleration due to gravity. The independence of the x- and y-components of the vector (inclined plane) allows us to evaluate motion solely in the vertical direction. We will further examine this independence when we move into projectile motion.

Physical Science - Test Monday! Don't forget to have your homework sheets and your calculators. Remember to study ALL material for this unit. On Tuesday, we start our unit on motion - the first of the Introductory Physics curriculum frameworks curriculum standards. You will find that we have previewed a good bit of this material in the Mathematics unit.

That's a wrap. Back to House...

Vectors

Honors Physics - Vector resolution and combining non-perpendicular vectors was the focus of the day, even though C Block was lost to peer mentor training. C block will catch up, lecture-wise on Monday. Remember to read tomorrow's lab this evening, so that you'll be ready to go when class starts. The first truly empirical method for determining the value of "g" was using an inclined plane and this lab will mimic that experience. It will also allow some practice with vector resolution.

Physics - we begin working with vectors tomorrow by investigating how vectors can be combined graphically. As a tool, vectors are very valuable for the analysis of physical phenomena and we will make extensive use of them during the course.

Physical Science - your daily objectives will be returned tomorrow so that you have them on hand as a study tool for Monday's exam. A note on these - some people were missing a number of days and some people didn't provide any answers. The daily objective expectations were outlined on the first day of class and have been reiterated several times since then. Most people did a good job! The one bit of criticism I would offer is to add detail to your answers so that the answers are thorough. Also, re-read your answers to see if they (a)make sense and (b) answer the question being asked. The daily objectives and answers will be collected periodically during the year, so use this as an opportunity to collect points.

Twisting Around

Honors Physics got a big face full of vectors today, but most people survived the experience. The graphical method of combining vectors is cumbersome and tedious, but it validates the "magic number" answers that you get when using trigonometry and will help you when we begin to draw free-body diagrams for analyzing forces. This activity demonstrated the tip-tail method for vector addition and the principle and the vectors can be added in any order and achieve the same resultant. Tomorrow, we will discuss the activity and the general principles of graphical analysis of vectors. If you borrowed a protractor from me today, remember to return it tomorrow.

Physics - due to picture day eating up E block yesterday, the test has been postponed one day. Tomorrow will be time for general review, so come with questions and issues that you would like to discuss in class. I will also have review problems ready for practice.

Physical Science - A final review of mathematics tomorrow and then the test on Thursday. EVERYTHING that we cover in the lecture, lab, textbook, etc. is fair game. This unit operated a great deal out of the note packet, rather than the textbook, so plan your study accordingly. Remember to bring your calculators and don't rely on me to be here early on Thursday morning to answer questions. Have questions ready tomorrow, so that you can use the answers to facilitate your studying on Wednesday night.

Skipping a Night

No real post. Got new laptop. Afternoon/evening dedicated to giving it love and attention...Here's a funny picture of a cat to tide you over...

Animals 'n Tech

This is EXACTLY the reason that I go wireless at home:


see more puppies

And this cat obviously read my book - Principles of Peripherals Repair

Gotta Love Those Formulas!

Physics - we are starting to head into the Land of the Fabulous Formula, from which we may never emerge. As you approach new formulas, whether simple or complex, remember that they are not your enemy. Look carefully at the variables they contain - we will have studied them and you do know what they are. Look at the mathematical operations - nothing beyond basic math skills. Order of operations might bite you if you aren't paying attention when you plug numbers into your calculator and you might have to perform some unit conversions, but these are little things that we can iron out in class. Write down the information you know and identify the type of measurement it represents (initial velocity, acceleration, etc.) Check you list of equations and decide which one makes best use of your information to find the desired answer. Sometimes, you have to add to your treasure trove of information by solving for a value that isn't your desired one, but is a value that will help you towards your final goal. So what? It is just one little additional step, and for this chapter, you are still working with the basic kinematics formula base. Monday's discusson of free fall will rely on the same equations that we used today, so you'll get more practice. Tuesday - general review. Wednesday - Chapter 2 exam. Be there or be square.

Physical Science - Monday's discussion of graphing will (again) be a review for you, but it will be an important review. We do a great deal of graphing and graph interpretation in this course and I expect that graphs will be properly formatted and presented when submitted with an assignment. LoggerPro will make many graphs for you, but homework problems and other lab activities will require that you craft graphs from data or interpret the information being presented by a graph. These are skills that will follow you through ALL of your science courses. For Wednesday's test, start gathering questions to bring to Tuesday's review. If you need additional help, see me on Monday to schedule a time. If you need extra problems for practice, get them Monday. Don't wait until the last minute to start preparing. I can't stress this enough.

Honors Physics - Motion studies start all physics courses and the basic kinematics formulas are the first set of "real" physics formulas that students encounter. They are good for giving you practice with formula-based problem solving and also for bringing critical-thinking skills to the problem-solving party. Some of your homework problems were straightforward. Some required brain-power. This will be the pattern for every topic that we encounter from now on. Don't forget calculators on Monday and don't neglect any portion of this chapter's work - lecture, lab, reading, etc.

g Whiz

Honors Physics - no one experienced grievous bodily harm during the performance of the lab so yeah for us! This lab quickly demonstrates acceleration due to gravity with very fine precision. Everyone's velocity/time graphs gave a slope very close to the accepted 9.81 m/s² value. For the extensions (tossing the object downwards or upwards), the values were not as close, but this is to be expected. Watching groups, the picket fence demonstrated some torque during the toss and this will affect acceleration. The values were, however, close enough for government work. Gravity does vary with location, but that should not have had a great influence on your data, as seen from the map of the Earth's gravitational field. The Northeast US pretty much falls at zero on the gravitational anomaly scale. Air resistance did affect the acceleration, as we would predict from daily observation of the world around us. Tomorrow, we'll go over your free-fall homework problems and have a general discussion about the chapter. Test Monday and,yes, I will give you the formulas and you can use your calculators.

Physics - Lots of graphs today, but graphs are one of the best ways to analyze motion. We will use graphs and coordinate systems often in class to address topics, so keep those skills close at hand. Often, a quick graph will help you understand more about a situation than a page full of calculations. Tomorrow, though, is calculation day as we take on the basic kinematics formulas. Make sure to have a calculator on hand.

Physical Science - Good questions in class today about the lab! We will further our examination of SigFigs and SciNot in lecture tomorrow and, hopefully, start to review basics about graphing. The exam for this chapter is scheduled for next Wednesday, so don't wait until the last minute to begin your preparations. Get extra help from me if needed, collect questions to ask in class, rework or get fresh problems from me, etc. You will need calculators for exams, so don't forget yours that day. I will give you any basic formulas or information that you might need (density/volume formulas, metric prefixes...), so don't worry about that piece.