My teacher has given me the opportunity to help raise my physics mark by doing an extra project, but it''s up to me to come up with a proposal for his approval. I was wondering if anybody had any ideas/suggestions as to what I might do? This should ideally be based on a more experimental project than research. However, a combination of the two could work well. Any help would be appreciated. Thanks in advance Etran

what''s the (active) topic of your physics class? physics is such a broad subject.

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My compiler generates one error message: "does not compile."

You could roll a ball down an incline plane and measure how long it takes to reach the bottom. You can then compare that for differant slopes of the incline. Your position with linear acceleration is s(t)=1/2*a*t^2+v0*t+s0 where s(t) is your position at time t, v0 is the velocity at time 0, s0 is the position at time 0 and a is your acceleration. If you measure distance along the incline with the starting position being zero then s0 is zero. The ball doesn''t start moving until you let go of it so v0 is zero. That makes it fairly simple to solve for a.

Now you can use trig to calculate the angle of the incline based upon the length of the incline the height of the elevated end. If you plot angle versus the acceleration you should roughly approximate a segment of a sine wave. So roughly a=c*sin(angle) where c is a constant where c is a constant, but it won''t be exact. a should equal c when the angle is 90 degrees, i.e. sin(90)=1, but if you measure accurately c will be a bit smaller. You can then try to explain that differance. Also c will vary a bit depending upon the angle of the incline and the variation isn''t all due to the accuracy of your measurement. You can try graphing the value you calculate for c versus the angle of the incline and also the value for c versus the time it took to reach the bottom. Compare the two and try to figure out what is contributing to the differance, i.e. does the differance increase or decrease with the elapsed time and angle. You might also want to graph the angle versus the time to see how those vary in relation to one another.

Overall the longer the board you are rolling the ball down the less your accuracy in measurement will matter. Also the type of ball and type of surface you are rolling it across matters so you want to use the same ball and same surface for a set of measurements at differant angles. You can change the ball and/or the surface to better understand what is going on, but you need to keep the measurements seperate. Repeat a given run, i.e. angle, surface and ball, several times to get a measure of your accuracy. Average the values you get and compare that to the individual measurements. That gives you some idea of whether you need to make adjustments to the experiment, i.e. use a longer board, and can also be used to get a sense of how much your results might vary just due to errors in measurement.

Thanks for the idea LilBudyWizer, but unfortunately we did something very similar last year. As to what we are studying, we are doing kinematics, ie. Newton''s 3 laws, universal gravitation, simple harmonic motion, projectiles, friction, torque. We are also doing electricity, magnetism and I believe also sound. It has to be something which is more advanced than what we do in class, although I could use the concepts we learnt, it would be best if they were used in situations that aren''t usually covered in an AP Physics course.

Etran

I took AP physics years ago (1983) and had to do a project. For my project, I built a seismograph, which was kind of cool. I got a B. One girl built a bridge out of some kind of polarized plastic, which allowed her to see the stress contours when weights were put on the bridge. Also cool. Plus, she was an EXTREMELY cute blonde, which I remember most of all. A real hottie. But the king of projects, the ultimate in AP physics projects, which one person (Brett Hanna I believe was his name) actually did in my class.....was to measure the gravitational constant G. Brett actually built a Cavendish Balance and, using tungsten wire, some high precision lasers and ultra stable platforms loaned by a generous local business, measured G. He was less than an order of magnitude off, which isn''t bad for a high school student.

If you like the gravitational constant idea, these pages may give some ideas on how you might do the experiment:

http://faculty.millikin.edu/~jaskill.nsm.faculty.mu/G.html

http://www.physics.brown.edu/Studies/Demo/solids/demos/1l1030.html

http://www.physics.brown.edu/Studies/Demo/solids/demos/1l1020.htm

http://www.upscale.utoronto.ca/IYearLab/cavend.pdf

I also built a small wind tunnel for a science project, which won a local county science fair and was entered in the state science fair. You could do something like that, and measure the lift curve vs. angle of attack of a simple wing.

Graham Rhodes
Senior Scientist
Applied Research Associates, Inc.

I love the idea of finding G but I need to get it approved by my teacher first, and if that happens, I think one of my hardest problems would be getting the required equipment. Where would one go to obtain such equipment or even just rent it out?

Etran

Just noticed, that first link is to my school. Well, I haven''t been there for 16 years now, but I got my degree there. Did that just come up on a search?

You could make a little tech. demo in which the player shot at different materials, with different projectiles, and the resulting sound was dynamically generated based on the physical properties of the objects?

I don''t know how you''d do it, but it would be quite cool.

Henrym
My Site

a couple of ideas:

Along the lines of intricate experiments, you could try to measure the speed of light by replicating Michelson''s experiment.

(I''m extremely impressed by the experiments mentioned here. My high school was pathetic.)

Perhaps more game-appropriate: build a simulation/visualization of smoke and/or fluids.

Author, "Real Time Rendering Tricks and Techniques in DirectX", "Focus on Curves and Surfaces"

pool table simulator

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