3/30/12
Electrostatics
C, E and F Blocks began their long journey through electricity today with an introduction to electrostatics. The property of charge was described, as were the forces it generated. We looked at Millikan's oil-drop experiment and how it demonstrated that charge was a quantized value and linked that to the law of conservation of charge. Time was also taken to describe three methods of charging (friction, conduction and induction) and we'll see some examples of those methods as we move through the chapter. On Monday, we hit the topic of electric force right in the nose and spend time with Coulomb's Law.
B Block worked on a lab that looked at electric discharge. Coulomb's law was used to determine the size of charges on two spheres and how basic ideas of force vectors could be used to work problems involving electric force. Folks had an interesting time working with that lab and we'll go over the results on Monday, when begin our discussion of electrostatics.
3/29/12
Evaulation Day
Everyone was engaged in their Chapter 15 and 16 exams, though C Block did have time to watch the solar power episode of Cool Fuel Roadtrip. Make sure those discussion questions are ready for me tomorrow. B Block needs to make sure that they do the assigned reading since tomorrow's lab will require a bit of brain power and prior knowledge on the topic of charge and electric forces. A review of force vectors and equilibrium will also come in handy. The rest of the folks will start their discussion of electrostatics with a definition of charge, properties of charge and methods of charging objects.
3/28/12
Review Day
Everyone was in review mode today, going over labs, diffraction problems or a combination of the two then moving on to walking through chapters 15 and 16 in preparation for tomorrow's test. On Friday, folks start electrostatics, with B Block working an investigation centering on Coulomb's Law. Sharpen those force vector skills...
3/27/12
Lasers Were Flying
Both C and E Blocks worked on their lab investigations that let them explore diffraction and its relation to wavelength and configuration of the diffraction grating. They used diffraction to determine the wavelength of two different laser pointers and to determine the slit separation of a mystery grating. We'll go over the lab in class tomorrow before embarking on our review for Thursday's test.
B and F Blocks finished up their discussion of diffraction (E Block finished theirs before their lab investigation) and linked that material with yesterday's work on interference. The homework problems will use the same formulas as for the interference problems, but you will have to determine slit separation using the #lines/cm property of the diffraction gratings. We'll run through these tomorrow for any questions before reviewing for Thursday's test.
3/26/12
Interference
B and E Blocks took up the topic of interference of light waves today. We looked at the conditions required to produce observable interference patterns for light (must be monochromatic and coherent)and discussed Young's double-slit experiment that was used to document these patterns and provide evidence for the wave theory of light. We practiced the relevant calculations for interference and will expand these tomorrow when we look at diffraction. For B Block, this will be in lecture; for E Block, this will be in lab.
C Block discussed diffraction in class today, although we'd been skirting around the issue with our interference lecture on Friday. Looking back at Friday's slides, it was easy to see that diffraction was necessary for the wave interference patterns formed and observed and today we looked at similar slides and tossed in Huygen's principle as a bonus. The lab activity we work on tomorrow will allow you to investigation diffraction of light and use the formulas from today to calculate the wavelength of the laser pointers you use in class.
F Block worked on their diffraction and interference lab today. Groups used a diffraction grating with a known slit separation to measure the wavelength of light of two laser pointers (a red, a green and/or a violet). Then, students were given a diffraction grating with an unknown slit separation and to design a test to document that property for the grating. The formula used for the calculations was introduced at the start of class and we'll get another look at it tomorrow when we talk about diffraction.
For everyone, Wednesday is review day; Thursday is exam day for Chapters 15 and 16. Friday, we start with charge and static electricity.
C Block discussed diffraction in class today, although we'd been skirting around the issue with our interference lecture on Friday. Looking back at Friday's slides, it was easy to see that diffraction was necessary for the wave interference patterns formed and observed and today we looked at similar slides and tossed in Huygen's principle as a bonus. The lab activity we work on tomorrow will allow you to investigation diffraction of light and use the formulas from today to calculate the wavelength of the laser pointers you use in class.
F Block worked on their diffraction and interference lab today. Groups used a diffraction grating with a known slit separation to measure the wavelength of light of two laser pointers (a red, a green and/or a violet). Then, students were given a diffraction grating with an unknown slit separation and to design a test to document that property for the grating. The formula used for the calculations was introduced at the start of class and we'll get another look at it tomorrow when we talk about diffraction.
For everyone, Wednesday is review day; Thursday is exam day for Chapters 15 and 16. Friday, we start with charge and static electricity.
3/23/12
Odds and Ends
Today was a strange day full of mish and mash...
B Block went over their refraction and lenses quiz before taking on the topics of total internal reflection and dispersion. We looked at how total internal reflection is generated and discussed examples of how it is used in fiber optic systems. We'd already touched on dispersion earlier in this unit, but reviewed the basics and went into more detail on formation of rainbows in the atmosphere.
C Block started their discussion of interference and diffraction with an overview of interference and Young's double-slit experiment. We linked the familiar ideas constructive and destructive interference with the new concepts of phase and fringes. Waves in phase produce constructive interference and a bright fringe on a screen; destructive interference is produced by waves that are out of phase and we see a dark fringe on the screen. On Monday, we'll add diffraction to the mix before taking Wednesday as a review day for Thursday's exam.
E and F Blocks were sparsely populated due to rampant dismissals for Frolic. Why juniors and seniors want to attend a freshman/sophomore dance is beyond me... anyway, those who remained got to investigate the myriad of science demonstrations around the room and spent the period playing with electricity, projectile motion, angular momentum, etc. A good time was had by all. On Monday, E Blocks begins their discussion of interference and diffraction and F Block conquers interference of light before working on a lab that centers on diffraction.
B Block went over their refraction and lenses quiz before taking on the topics of total internal reflection and dispersion. We looked at how total internal reflection is generated and discussed examples of how it is used in fiber optic systems. We'd already touched on dispersion earlier in this unit, but reviewed the basics and went into more detail on formation of rainbows in the atmosphere.
C Block started their discussion of interference and diffraction with an overview of interference and Young's double-slit experiment. We linked the familiar ideas constructive and destructive interference with the new concepts of phase and fringes. Waves in phase produce constructive interference and a bright fringe on a screen; destructive interference is produced by waves that are out of phase and we see a dark fringe on the screen. On Monday, we'll add diffraction to the mix before taking Wednesday as a review day for Thursday's exam.
E and F Blocks were sparsely populated due to rampant dismissals for Frolic. Why juniors and seniors want to attend a freshman/sophomore dance is beyond me... anyway, those who remained got to investigate the myriad of science demonstrations around the room and spent the period playing with electricity, projectile motion, angular momentum, etc. A good time was had by all. On Monday, E Blocks begins their discussion of interference and diffraction and F Block conquers interference of light before working on a lab that centers on diffraction.
3/22/12
With Refraction You Get
Well, for B Block... nothing, since they had their quiz after we went over their lenses and refraction lab. But, for everyone else, we looked at total internal reflection (the basis of fiber optics) and dispersion (the basis of rainbow formation). For total internal reflection, you should know the basic definition and its relationship to the critical angle. You should also be able to calculate the critical angle for a pair of substances using Snell's Law. We looked at some examples of total internal reflection, starting with a man-mad example (fibers from a cheap fiber-optic Christmas-tree thingie) and then moved on to a natural example (ulexite or television stone).
Attention then turned to dispersion and its consequences. With a material with a high index of refraction, the separation of light due to different paths of travel for different wavelengths is a well-loved phenomenon. In the atmosphere, light has to rely on a second event - total internal reflection - to have enough travel time in the rain drop to show good separation of colors. We looked at some variations of rainbows, such as double rainbows and lunar rainbows, but folks should have a solid idea of how a single rainbow forms and how prisms disperse light.
Tomorrow, we start interference and diffraction - the last two behaviors of light we'll study - before moving on to electricity.
Attention then turned to dispersion and its consequences. With a material with a high index of refraction, the separation of light due to different paths of travel for different wavelengths is a well-loved phenomenon. In the atmosphere, light has to rely on a second event - total internal reflection - to have enough travel time in the rain drop to show good separation of colors. We looked at some variations of rainbows, such as double rainbows and lunar rainbows, but folks should have a solid idea of how a single rainbow forms and how prisms disperse light.
Tomorrow, we start interference and diffraction - the last two behaviors of light we'll study - before moving on to electricity.
3/21/12
Surprise!
C, E and F Blocks reviewed their refraction and lenses homework and then got a nice pop quiz to play with for the rest of the period. E Block honors students had to work alone, but with notes and homework. C and F Blocks got to work in groups with their notes and homework. We'll go over these quizzes tomorrow before moving on to total internal reflection and dispersion.
B Block worked on their Lenses and Image Formation lab. The patterns we discussed in class about how changing object position affected image size, position and type were easily demonstrated by your data and we even got to examine the divergence of light by a double-concave lens (used to determine the focal point). We'll go over the lab tomorrow, so make sure to have all calculations and graphs completed.
B Block worked on their Lenses and Image Formation lab. The patterns we discussed in class about how changing object position affected image size, position and type were easily demonstrated by your data and we even got to examine the divergence of light by a double-concave lens (used to determine the focal point). We'll go over the lab tomorrow, so make sure to have all calculations and graphs completed.
3/20/12
Lenses and Image Formation
Everyone was on lenses today and the patterns of image formation as you move an object in respect to the position of the lens. B, E and F Blocks reviewed their ray diagrams before looking at converging and diverging lenses, in terms of image formation, and found that for converging lenses, as you approach the lens the image gets larger and farther from the lens (while remaining real) until you reach the focal point. At the focal point the image forms at infinity (which was why E and F Blocks couldn't get a clear image of their object on their screen in lab) and within the focal length, the image gets smaller and closer to the lens as the object approaches the lens and are now virtual. The diverging lens is a simpler beast - all of the images are virtual, upright, smaller than the object and form within the focal length for any object position. We'll go over your problem-solving homework tomorrow before taking a look at total internal reflection. Well, E and F Blocks will do that while B Block works on their laboratory exercise.
C Block did work on their laboratory exercise today to examine patters to image formation by converging lenses and how measuring light divergence can let someone determine the focal length of a diverging lens. Have your lab questions/graph ready tomorrow so we can review these ideas in class.
C Block did work on their laboratory exercise today to examine patters to image formation by converging lenses and how measuring light divergence can let someone determine the focal length of a diverging lens. Have your lab questions/graph ready tomorrow so we can review these ideas in class.
3/19/12
Only Tangentially Relevant
The Higgs Boson always occupies some portion of the science press... here's an explanation of it that I think works very well...
Bending That Light
Today was all about lenses and image formation and groups endured either the math involved with predicting image properties or using ray diagrams to analyze image formation by lenses.
B, E and F Blocks took their first steps with lenses today (well, E and F Blocks do have some lab experience in this area). The characteristics of converging and diverging lenses were examined and their abilities form images was explored. We spent time working through the construction of a ray diagram for a converging lens making a real image and folks have some more of these to do for homework. B and E Blocks also have a virtual image to deal with, so don't forget that you have a nice textbook to help you with that (might check page 571), but F Block only has to worry about real image formation. We'll look over these tomorrow before moving on to using the thin-lens formula and magnification formulas to more precisely hammer down numbers for image position and size.
C Block reviewed their ray diagrams and used those diagrams as examples to help clarify the relationship between object position and type/size of image formed for converging lenses. As you move the object towards the lens, the real image formed grows in size and moves away from the lens (q and M increase). At the focal point, the image forms at infinity and if you continue to push the object forward, the image now becomes virtual, with image distance and magnification increasing as you progressively approach the lens. We then started working on the math involved with lenses to put some precise values for our image properties and your homework tonight will give you additional practice working with the thin-lens and magnification formulas. We'll go over this and the 15.1 homework tomorrow before starting your lab on lenses.
B, E and F Blocks took their first steps with lenses today (well, E and F Blocks do have some lab experience in this area). The characteristics of converging and diverging lenses were examined and their abilities form images was explored. We spent time working through the construction of a ray diagram for a converging lens making a real image and folks have some more of these to do for homework. B and E Blocks also have a virtual image to deal with, so don't forget that you have a nice textbook to help you with that (might check page 571), but F Block only has to worry about real image formation. We'll look over these tomorrow before moving on to using the thin-lens formula and magnification formulas to more precisely hammer down numbers for image position and size.
C Block reviewed their ray diagrams and used those diagrams as examples to help clarify the relationship between object position and type/size of image formed for converging lenses. As you move the object towards the lens, the real image formed grows in size and moves away from the lens (q and M increase). At the focal point, the image forms at infinity and if you continue to push the object forward, the image now becomes virtual, with image distance and magnification increasing as you progressively approach the lens. We then started working on the math involved with lenses to put some precise values for our image properties and your homework tonight will give you additional practice working with the thin-lens and magnification formulas. We'll go over this and the 15.1 homework tomorrow before starting your lab on lenses.
3/16/12
Lenses
Some folks worked with lenses today, either in lecture or in lab, while others toodled through the basics of refraction.
B and F Blocks took time to get a general understanding of the phenomenon of refraction and how a material's index of refraction impacts the speed, wavelength and path of travel for a ray of light. We linked refraction and index of refraction to dispersion of light by prisms and relied on the law of refraction and Snell's Law to put some actual numbers to our general descriptions. On Monday, we'll move onto lenses, which F Block investigated yesterday and B Block will explore next Wednesday.
C Block started their work on lenses today. We defined what is and isn't a lens and investigated image formation by both converging and diverging lenses. With those ideas in mind, we moved to better describe image formation through the use of ray diagrams. Like I said in class, I wont' ask you to craft a ray diagram for a diverging lens or for a converging lens when it is making a virtual image. However, you should be able to draw one for a converging lens making a real image, as we practiced. Tonight's homework will let you start to examine the relationship between object placement and type, size and position of image and we'll throw the more precise calculations into the mix on Monday.
E Block worked on their Image Formation by Lenses lab, testing both converging and diverging lenses. The converging lens gave you nice, real images that you caught on a screen and let you form a virtual image that you had to look through the lens to see. The diverging lens only makes virtual images, but you could at least use the divergence of the rays from the laser pointer to back-calculate the focal length of the lens. We'll go over this lab on Monday before moving to a more in-depth treatment of lenses.
B and F Blocks took time to get a general understanding of the phenomenon of refraction and how a material's index of refraction impacts the speed, wavelength and path of travel for a ray of light. We linked refraction and index of refraction to dispersion of light by prisms and relied on the law of refraction and Snell's Law to put some actual numbers to our general descriptions. On Monday, we'll move onto lenses, which F Block investigated yesterday and B Block will explore next Wednesday.
C Block started their work on lenses today. We defined what is and isn't a lens and investigated image formation by both converging and diverging lenses. With those ideas in mind, we moved to better describe image formation through the use of ray diagrams. Like I said in class, I wont' ask you to craft a ray diagram for a diverging lens or for a converging lens when it is making a virtual image. However, you should be able to draw one for a converging lens making a real image, as we practiced. Tonight's homework will let you start to examine the relationship between object placement and type, size and position of image and we'll throw the more precise calculations into the mix on Monday.
E Block worked on their Image Formation by Lenses lab, testing both converging and diverging lenses. The converging lens gave you nice, real images that you caught on a screen and let you form a virtual image that you had to look through the lens to see. The diverging lens only makes virtual images, but you could at least use the divergence of the rays from the laser pointer to back-calculate the focal length of the lens. We'll go over this lab on Monday before moving to a more in-depth treatment of lenses.
3/15/12
Refraction for All!
Today began our journey through the world of refraction and lenses (aka Chapter 15). B Block had to go it alone since I was summoned to talk with parents of incoming freshmen for scheduling concerns, so they slogged through Snell's Law and the law of refraction on their own. Tomorrow, we'll add some explanation to all of that...
C and E Blocks discussed the phenomenon of refraction - the change of speed, direction and wavelength of light when it changes media - and how to quantify the speed and direction change. Be very clear about what happens when light enters a more denser material (slows down, shorter wavelength, path closer to normal line) and when it enters a less dense medium (faster speed, longer wavelength, path diverges from normal line). We looked at the property of transparent materials called the index of refraction and what that meant in terms of wave speed in that material. Lastly, we related the phenomenon of dispersion to refraction. In materials with a significant index of refraction like a diamond or quartz, there is a very noticeable difference in the speed changes and path of travels for the different colors of light. Tomorrow, apply refraction to yet another concept - image formation by lenses.
F Block worked on their lens lab during long block. Both converging and diverging lenses were investigated for patterns of image formation. As with converging mirrors, converging lenses can make real or virtual images dependent on placement of the object. Diverging lenses, like diverging mirrors, can only form virtual images smaller than the object. We'll dive into this topic in detail on Monday, but tomorrow is set aside to get a handle on refraction and how to evaluate the effects of refraction on the motion of light.
C and E Blocks discussed the phenomenon of refraction - the change of speed, direction and wavelength of light when it changes media - and how to quantify the speed and direction change. Be very clear about what happens when light enters a more denser material (slows down, shorter wavelength, path closer to normal line) and when it enters a less dense medium (faster speed, longer wavelength, path diverges from normal line). We looked at the property of transparent materials called the index of refraction and what that meant in terms of wave speed in that material. Lastly, we related the phenomenon of dispersion to refraction. In materials with a significant index of refraction like a diamond or quartz, there is a very noticeable difference in the speed changes and path of travels for the different colors of light. Tomorrow, apply refraction to yet another concept - image formation by lenses.
F Block worked on their lens lab during long block. Both converging and diverging lenses were investigated for patterns of image formation. As with converging mirrors, converging lenses can make real or virtual images dependent on placement of the object. Diverging lenses, like diverging mirrors, can only form virtual images smaller than the object. We'll dive into this topic in detail on Monday, but tomorrow is set aside to get a handle on refraction and how to evaluate the effects of refraction on the motion of light.
3/14/12
Test Day!
Everyone except the skippers endured their light and reflection tests and will start on refraction tomorrow. F Block will be working on a lab that lets them investigation formation of real and virtual images by lenses and the rest of the folks will be looking at the phenomenon of refraction and how to predict the direction of refracted light rays using Snell's Law. See you then!
3/13/12
Combo Post
Didn't a chance to post yesterday, but everyone knows what we did so who really cares? B Block worked on their light intensity and polarization lab, which we discussed in class today and reinforced the ideas that we went over in our class lectures. C, E and F Blocks took time to go over the ideas of color and polarization. We had already done lab work on polarization, so that concept flowed smoothly, but folks usually have a little trouble with the additive and subtractive color systems. Understanding the systems is not hard, but understanding what you would see when you mix colors of light or pigment or shine light on a colored object can be troublesome. We took time in class today to go over that homework and try and get everyone on board before we took our customary walk through the chapter material (also applies to B Block)in preparation for tomorrow's test. Remember your sign conventions for your mirror problems, forget about parabolic mirrors and make sure you can draw a ray diagram for real image formation by concave mirrors. I'm in before school tomorrow, so stop by if you need any last minute help. Starting on Thursday - refraction and lenses!
3/9/12
Phryday!
B Block took on the challenge of color and polarization today. We looked at the additive and subtractive color systems and looked at a few demonstrations to see how additive color works for televisions and computer screens and subtractive color systems work using a spectrophotometer. We then hit polarization and discussed how light could become polarized through passing through a filter, reflection or scattering. We also took time to look at how a polarizing filters could be used to block previously-polarized light and how that related to sunglasses and camera lenses. On Monday, a lab about light intensity and polarization.
C Block worked on their light intensity and polarization labs today and found, as expected, that the relationship between light intensity and distance is an inverse-square one. We spent enough time on that between sound and the first part of this chapter that it should be pretty easy to write the Conclusion part of your write-up for that piece of the lab. For polarization, you used one filter to polarize light and a second (the analyzer) to demonstrate how light penetration changes with angle of analyzer. The sunglasses lens showed the same pattern, so both nicely followed Malus's law, which we'll touch on in class Monday.
E and F Blocks discussed curved mirrors in class, both concave and convex, and how examined how these mirror types formed images. We contrasted real with virtual images, explained how to use the mirror equation and magnification formulas and looked at how to draw ray diagrams for these mirror types. Remember that you are only responsible for drawing ray diagrams for concave lenses forming real images, but be sure you can do that quite well for the test. On Monday, we take a look at color and polarization.
C Block worked on their light intensity and polarization labs today and found, as expected, that the relationship between light intensity and distance is an inverse-square one. We spent enough time on that between sound and the first part of this chapter that it should be pretty easy to write the Conclusion part of your write-up for that piece of the lab. For polarization, you used one filter to polarize light and a second (the analyzer) to demonstrate how light penetration changes with angle of analyzer. The sunglasses lens showed the same pattern, so both nicely followed Malus's law, which we'll touch on in class Monday.
E and F Blocks discussed curved mirrors in class, both concave and convex, and how examined how these mirror types formed images. We contrasted real with virtual images, explained how to use the mirror equation and magnification formulas and looked at how to draw ray diagrams for these mirror types. Remember that you are only responsible for drawing ray diagrams for concave lenses forming real images, but be sure you can do that quite well for the test. On Monday, we take a look at color and polarization.
3/8/12
Reflection
Today was a day of reflection - HAH!
B and C Blocks took up the topic of curved mirrors and image formation. We looked at how both mirror types create images, contrasted real and virtual images, worked with the mirror equation and the two magnification formulas and discussed the construction of ray diagrams. Remember that I won't ask you to draw a ray diagram for a virtual image on a test, but I will ask you to do one for a real image and use the appropriate formulas for any type of image formation. Tomorrow, C Block works on their light intensity and polarization lab and B Block moves on to color and polarization.
E and F Blocks talked about reflection and image formation by plane mirrors. We contrasted specular and diffuse reflection and showed how the law of reflection accounted for both reflection types. We then turned attention to plane mirrors and how/why the formed their particular type of image. Remember that plane mirrors form virtual, upright images the same size and distance from the mirror as the object. Tomorrow, we'll complicate things by taking up the challenge of curved mirrors.
B and C Blocks took up the topic of curved mirrors and image formation. We looked at how both mirror types create images, contrasted real and virtual images, worked with the mirror equation and the two magnification formulas and discussed the construction of ray diagrams. Remember that I won't ask you to draw a ray diagram for a virtual image on a test, but I will ask you to do one for a real image and use the appropriate formulas for any type of image formation. Tomorrow, C Block works on their light intensity and polarization lab and B Block moves on to color and polarization.
E and F Blocks talked about reflection and image formation by plane mirrors. We contrasted specular and diffuse reflection and showed how the law of reflection accounted for both reflection types. We then turned attention to plane mirrors and how/why the formed their particular type of image. Remember that plane mirrors form virtual, upright images the same size and distance from the mirror as the object. Tomorrow, we'll complicate things by taking up the challenge of curved mirrors.
3/7/12
John Carter
There is a lot of negative buzz about the upcoming Disney film - John Carter- and that bums me out. Growing up, Edgar Rice Burroughs books held a very prominent position on my bookshelf. His Mars books were great - lots of sci-fi and loads of action - who could ask for more? I have no idea what the movie version is going to be like, but the first book in the series - A Princess of Mars - is a killer read. You can read it for free (legally) from Project Gutenberg, where you can find more of the Mars books and his Tarzan books, too (Edgar Rice Burroughs at Project Gutenberg).Do yourself a favor and read some of those classic sci-fi authors... you'll be glad you did.
Light and Reflection
B and C Blocks discussed the phenomenon of reflection in class today. Diffuse and specular reflection were contrasted and tied into the law of reflection. Make sure you're clear that rough surfaces still obey the law of reflection, but since the normal line at different points are aligned in different directions, the directions of the reflected rays will be different, also. We also took time to look at the reflective properties of plane mirrors and were introduced to the concepts of the virtual image and the ray diagram. We'll use ray diagrams a lot in this unit, so practice them and make sure you an contrast the properties of virtual images with those of real images.
E Block worked on their light intensity and polarization labs. As expected, light intensity shows an inverse-square relationship with distance from source, but the polarization material was something we didn't hit on in previous chapters. We'll delve into polarization at the end of this chapter, but put on your thinking caps tonight to come up with answers to your lab extension questions.
F Block started their discussion of light in class today after we reviewed the light intensity and polarization labs. We reviewed the basic properties of electromagnetic waves and the electromagnetic spectrum, then took a look at Huygen's principle and his idea of wavelets. The class ended with a quick review of light intensity and a forward look at tomorrow's work on reflection and flat mirrors.
E Block worked on their light intensity and polarization labs. As expected, light intensity shows an inverse-square relationship with distance from source, but the polarization material was something we didn't hit on in previous chapters. We'll delve into polarization at the end of this chapter, but put on your thinking caps tonight to come up with answers to your lab extension questions.
F Block started their discussion of light in class today after we reviewed the light intensity and polarization labs. We reviewed the basic properties of electromagnetic waves and the electromagnetic spectrum, then took a look at Huygen's principle and his idea of wavelets. The class ended with a quick review of light intensity and a forward look at tomorrow's work on reflection and flat mirrors.
3/6/12
Light!
Today we entered the world of light and reflection. B, C and E Blocks discussed the properties of light as an electromagnetic wave (though we did give a nod to the particle nature of light), took a brief look at Huygen's principle and trod over old ground with the concept of intensity. Tomorrow, E Block will work on their light intensity and polarization lab (F Block's activity today) and B and C will push on to reflection.
F Block conducted two lab investigations - one on light intensity and the other on polarization. For light intensity, the inverse-square relationship between intensity and distance from the source was pretty clearly demonstrated and matched what we would predict from our work with sound intensity. The polarization lab let folks work with polarizing filters to see how they function and a polarizing sunglass lens was tested to see if it followed the basic pattern as the filters (it did). Tomorrow, we take up the concepts of properties of light, Huygen's principle and review the math behind light intensity.
F Block conducted two lab investigations - one on light intensity and the other on polarization. For light intensity, the inverse-square relationship between intensity and distance from the source was pretty clearly demonstrated and matched what we would predict from our work with sound intensity. The polarization lab let folks work with polarizing filters to see how they function and a polarizing sunglass lens was tested to see if it followed the basic pattern as the filters (it did). Tomorrow, we take up the concepts of properties of light, Huygen's principle and review the math behind light intensity.
3/2/12
Exam Day
Everyone endured their Chapter 13 - Sound tests today and everyone starts on Light and Reflection on Monday. That is the first chapter of three that deals with light and light-based phenomena. We'll be looking at the properties of light and color, the workings of mirrors and lenses, why polarizing sunglasses work the way they do, how rainbows form and all sorts of other things. Should be a fun ride...
3/1/12
Goodbye Loose Ends
Today was the settling of all affairs relevant to sound in preparation of tomorrow's assessment. B Block had a page-by-page review of the material after going over their Speed of Sound lab and harmonics/beats homework, then moved to an investigation that let folks look at how musically is structured mathematically. Note to people working on their graphs - it is not a quadratic relationship. If you think about what is actually going on, your brain might turn in another direction. We'll go over this lab on Monday and see what people came up with.
C Block went over their Speed of Sound and Mathematics of Music labs before turning attention to test review. It was nice to see that the speed of sound did increase with increasing temperature as we would predict and that music is an exercise in math, especially an exercise in ratios.
Since we reviewed yesterday, E Block was divided between people who wanted to study for tomorrow's test and those who wanted to investigate music. Those people will get a little lab bonus for their work, but hopefully, didn't need the time to succeed on tomorrow's assessment.
F Block went over their harmonics/beats homework, then had a page-by-page review of the material for tomorrow's test. I'm here before school if anyone needs anything at the 11th hour.
C Block went over their Speed of Sound and Mathematics of Music labs before turning attention to test review. It was nice to see that the speed of sound did increase with increasing temperature as we would predict and that music is an exercise in math, especially an exercise in ratios.
Since we reviewed yesterday, E Block was divided between people who wanted to study for tomorrow's test and those who wanted to investigate music. Those people will get a little lab bonus for their work, but hopefully, didn't need the time to succeed on tomorrow's assessment.
F Block went over their harmonics/beats homework, then had a page-by-page review of the material for tomorrow's test. I'm here before school if anyone needs anything at the 11th hour.
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