Free at Last!

Seniors finished their exams today and have officially left the building. Of course, they still have to return to make up missed work, turn in their books that they forgot to bring to class this week, plead with teachers for that "one extra point" that will tip their grade to the next level, etc., but the principle still holds. Juniors in Physics and Honors Physics will spend the rest of the year as slaves to my will - they are going to bench test the new Vernier Dynamics Tracks that the GEF funded through their grant program (Thank you again!), explore new labs to supplement the current lab program, preview physics videos for next year's classes...all things that will beef up their physics knowledge and help me out a great deal. And yes, it will count for a grade so don't plan on being slackers...

Physical Science completed their Magnetism exam today with a class average of 80%. Remember to keep the nose to the grindstone until the end of next week for prime MCAS performance. Monday's practice test will give you an idea of what to expect. BTW: I will post the answers to the MCAS Electromagnetism Practice on the class website later this evening. I'd suggest answering the questions as though they were an actual test and then checking your score. Isolate areas of strength and weakness and use that to guide your review for that topic.

Oh Yeah!

Hulu has Carl Sagan's Cosmos!

Trekkin' Closer

The medical tricorder - witness it's larval stage

Seniors are Done with Me

Yeehah! All the seniors in Physics and Honors Physics are done with their work and exams and only the juniors are left to suffer. We'll continue the year with extra labs, films and other enrichment pieces that we've not had the time to do during the regular curriculum. No, it will not be nap period...

Physical Science reviewed magnetism today in preparation for tomorrow's exam. Remember to have the homework that went over in class today ready to submit before the exam tomorrow. We'll use the practice MCAS exam on Monday to gauge how well-prepared are folks and address any areas that people would like to review, however, it would be a very good idea for people to gather questions over the weekend to bring into class next week.

Countdown to Zero Hour

Seniors are not counting the seconds until their final, ummm..., final is completed on Friday. Teachers are also, so happiness is spread around nicely. Physics is working on voluntary bonus work and Honors Physics spent today on last-minute preparations for tomorrow's exam.

Physical Science spent a long block discussing electromagnetic induction. Seems like a lot of information was hurled at you today, but if you filter it, a few major ideas shake out. The definition of electromagnetic induction, the definition of magnetic flux and ways to create magnetic flux, the relationship between degree of magnetic flux and current generated, the function of a generator and how it compares to an electric motor, the definition of alternating current and why generators and transformers are related to alternating current, how energy conversions are demonstrated by electric motors and generators and the function of transformers. I wouldn't spend a great deal of study time for Friday's exam on the parallel/perpendicular pieces for coil and magnetic fields, the variable designations for magnetic field and flux or the behavior of charged particles in magnetic fields. The origin and propagation of electromagnetic waves was already covered in previous material and today's discussion should simply have been review and clarification of those ideas. Tomorrow, a general review of this chapter and Friday is the exam. Starting Monday, we begin MCAS review with a whole exam from a previous academic year. Then, we'll tackle any specific concepts that people want to go over along with a cursory review of the frameworks topics. Next Thursday and Friday - the show is on...

Here's an interesting video on how electric transformers are made:



A cheap, simple generator that you can make at home:



Finally, a clear example of the fact that generators function to convert mechanical energy into electric energy:

No...

...this is not me with my first PC

On To Induction

The generation of electric current through varying magnetic fields is the final step in Physical Science's study of magnetism. Exam on Friday and Monday-Wednesday of next week will center on reviewing for the MCAS exam. Again, you should already have been engaged in independent review for this exam, as it covers the Introductory Physics curriculum frameworks - basically everything we've done this year. Physics took their senior final exam and Honors Physics spent time preparing for their final exam on Thursday. Busy day in payment for a long weekend...

As SandsThrough The Hour Glass

The 2008-2009 Introductory Physics MCAS exam is nearly upon us (June 4,5). Students should have already begun preparations, but as an assist, I cobbled together a website with a variety of online resources. I'll check through it over the next few days and add in additional video resources for the electromagnetism section, but its sufficiently ready for people to use in their study regimen. I'll toss a link over to the right, also, for when this post gets buried...

Like I Always Say

Freaky Friday

Physics and Honors Physics were basically on hold due to Senior Skip Day. Hope they don't fry in the sun...

Physical Science worked their magic with their electric motors, but they have not ascended to Harry Potter levels. Most of the difficulties that I noticed were mechanical in nature and can be remedied with some rebuilding. Think about things over the weekend. A few people took some spare kits, so they should be able to do some serious troubleshooting in the next few days. On Tuesday, one final round of problem-solving will be affected, so be prepared to go all out for those motors! Have a good long weekend!

Here's a pretty picture to start the relaxation: The Seahorse of the Large Magellanic Cloud

And A Good Time Was Had By Some

Physics and Honors Physics endured their exams for the electricity unit, their last exam before the final next week. Enough said about that.

Physical Science spent their lab period constructing their electric motors. As stated in class, this activity was a "trial by fire" and students were only allowed to ask me to supply them with additional materials. No construction help or advice was forthcoming. Students should take time tonight to consider where they are in the build process and think about how to address any issues or troubles that they were encountering towards the end of the period. Troubleshooting is often the most time-consuming part of a project, but it is a great way to get to truly understand how a device works. We will finish up with this activity tomorrow and then turn our attention to the generation of electricity using magnetism. Keep your eye on June 4 and 5 - MCAS is looming...

And More Wires

Physical Science built electromagnets today and researched how the number of windings influenced the strength of the magnetic field. As we discussed in class, the magnetic field generated in a current-carrying wire is fairy feeble, but coil the wire into loops and the magnetic field of each loop adds to the field of its neighbors and the result can be quite significant. Add an iron core and a true electromagnet (as opposed to a solenoid) is born. I was puzzled, though, by how many groups had difficulty wiring the circuit. After an entire unit on electricity and circuits, I had not expected to find groups with wire ends flapping in the breeze, creating open circuits. Also, remember that lab directions are there for a reason - read them and follow them. Tomorrow, that will be of great importance as you build your electric motors. Make sure to read the instructions tonight to familiarize yourself with the pieces and assembly directions. Take time to read over the troubleshooting section and the synopsis of motor theory.

Physics and Honors Physics tied up all loose ends for the electricity exam tomorrow. As usual, I'll be haunting my classroom before school if you have any questions. Do take time to peruse the sample final exams that I handed out today and don't forget to take home your copy of the final exam formula sheet. Physics - you're on deck Tuesday; Honors Physics is on the chopping block on Thursday. The sample finals are good examples of what to expect in terms of exam length, scope and question organization. Honors Physics will have ample time to discuss any problems with me before their exam, but Physics is short on time. Email me over the weekend if you have any issues and I'll respond as soon as possible. Just remember, this situation is unlikely to occur:

Circuits A'Flyin'

Honors Physics worked tirelessly to unravel the mysteries of series and parallel circuits. I_eq and R_eq for circuits and voltage drop and current across individual loads was measured and correlated with the theory we discussed in class. Some groups did not quite complete the lab activity, but we will go over the data patterns tomorrow, so you can fill in your lab sheets with the relevant information. Also, tomorrow, we will review tonight's homework and outline the material that you can expect on Thursday's exam.

Physics completed their discussion of circuit types and electric power in class today. First off tomorrow, we will go over the homework assignment and then tie up the electricity unit with an overview of electric safety devices - fuses, circuit breakers and ground-fault interrupters. We will outline Thursday's exam material and have time to discuss any issues or questions about Tuesday's final exam. Bring along any questions that you have so that we can maximize the use of our class time.

Physical Science examined further the ability of electric current to generate magnetic fields. The structure and function of galvanometers and motors was discussed and demonstrated and we'll add speakers to the list later in the week. Tomorrow - a quick lab on the construction of electromagnets and, on Thursday, another activity where you will have the opportunity to construct an electric motor. We should also have time that period to begin discussing the ability of magnetism to generate electricity- the basis of generator function.

What Is Up With Cats Lately?

Murky Monday

Physical Science sat through NOVA’s Magnetic Storm video that examined the nature of Earth’s magnetic field, its importance for protecting the earth from solar and cosmic radiation and how we might have to without it for a little while (just a couple of thousand years or so) until it reverses direction as it has done oh-so-many times in the past. Finish up those video questions and be ready to discuss them in class tomorrow. We’ll then continue on with our examination of electromagnetism. On Wednesday, a lab on making electromagnets is on the docket.

Physics concluded their discussion of electrical resistance and Ohm’s Law and began to move through the basics of electric circuits. We are skipping over capacitors due to time constraints and that material will not be on Thursday’s exam. Between tomorrow and Wednesday, we will conclude our discussion of circuits and electric power. Since Wednesday is a long block, we will also have time to review for Thursday’s exam.

Honors Physics were presented with information about series and parallel circuits and the patterns for voltage, current and resistance for the entire circuit and for individual loads for each circuit type. Tomorrow’s lab will allow you to validate these relationships and get practice wiring series and parallel circuits. Even though you will be using the Vernier circuit boards and the lab sheets will give you a general, labeled schematic diagram for each experimental configuration, not all details will be present in the diagram. For instance, they might show you that a parallel connection is called for, but they won’t show you exactly how to physically construct that connection with the resistors, voltage probe and alligator clips. That’s for you to work out….Wednesday, a discussion of the lab and the completion of the material for the unit. Thursday, exam. Friday, next Tuesday and Wednesday – review for the final exam.

If Only It Was This Easy

Dogs are Nefarious

Apparently, I'm not the only one who has pooches with minds of their own. Joseph Mallozzi, one of the Stargate writers, has his own pack of devious dogs. After getting their own Twitter account, the dogs leaked the working title of the upcoming Stargate: Atlantis movie! Read the terrible tale on Mallozzi's blog and saw the proof on the dogs Twitter page. If you apply some serious code-cracking skills, you can decipher their cryptic messages and the links give you visual proof of the workings of their active minds...

Prom Night

Half of the day was very quiet due to the lack of students because of dismissals for prom preparation. This morning, though, was quite busy as Physics conducted a lab centered around Ohm's Law, Physical Science began to discuss electromagnetism with the introduction of the right--hand rule and the function of solenoids and electromagnets, and Honors Physics completed their examination of capacitors and began to focus on the structure and function of electric circuits. For Physics and Honors Physics - expect a test next Thursday on the Electricity unit and use your note packets to guide your studying. Physical Science - you will have a test on magnetism prior to the MCAS exam. Hope everyone has a good weekend and a same Junior/Senior prom.

Electromagnetism

Now that Physical Science has undertaken a study of magnetism, it can be said that the entire physics curriculum is currently devoted to that broad and profoundly important field of electromagnetism. Yesterday, Physical Science explored the shape and strength pattern of the magnetic field surrounding a bar magnet. It was clear that field strength increased near the magnet's poles and weakened at a distance from these poles, even when measured along the body of the magnet. The north and south poles had equal, but opposite, field strengths. Today's discussion centered around hard and soft magnets, the nature of magnetic fields and forces and how to draw and interpret magnetic field lines. Tomorrow, we will continue our discussion about the Earth's magnetic field and the function of compasses. Note: as we discussed in class today, magnet strength can vary greatly, as illustrated below:



Physics continued their discussion of voltage, resistance and current and bundled these concepts into Ohm's Law. A Block will conduct a lab investigation of Ohm's Law tomorrow, but most everyone in E Block will be dismissed for prom preparations. We will not make up this lab for E Block, so the basic results were discussed in class today.

Honors Physics conducted the Ohm's Lab today and the results were very good. For resistors, a graph of voltage vs. current produced tight straight lines for which the slope was the value of the tested resistor. For the light bulb, a non-ohmic device, the graph demonstrated a non-linear relationship. For low voltages, resistance did not increase as quickly as for higher voltages. Explains why light bulbs typically burn out right when you turn them on - low resistance with increasing voltage means proportionally greater current draw. This increased current can over-tax a older filament, leading to breakage. Tomorrow, C Block will further its discussion of capacitors and enter into the arena of circuits. Activities in G Block will depend upon attendance due to prom dismissals.

Back in the Saddle

Finally! I can type without my wrist sending me messages of sour disapproval. Today, Physics conducted a lab investigating the nature and effects of static electricity. Honors Physics discussed the structure and function of batteries and the nature of electrical resistance. Physical Science endure their unit exam for electricity. Tomorrow, we begin our final MCAS unit - magnetism - with a lab investigation on magnetic fields of permanent magnets. Once we have completed the MCAS experience, attention will turn to atomic structure. Physics and Honors Physics are in their last unit before the final exam. The end is near...