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course PHY 241
12/4/201111:01 pm
These are in no particular order, as my binder is a complete mess of notes. I also listed two experiments I know that I have to either do or redo, but I'm pretty sure they're one or two others that I haven't done but don't know about" "
Lab Report
University Physics I
Equilibrium Experiment
Description: Take a long piece of Styrofoam, and place a domino on one of the far ends. Then, place two dominoes on the other end, at any distance, and find the point of equilibrium.
Data:
Length of Styrofoam: 28 cm
Distance of left domino from center: 14 cm
Distance of far right domino from center: 14 cm
Distance of second right domino from center: 8 cm
Distance of equilibrium from center: 2.5 cm right of center
Explanation: This experiment allowed us to find the difference in force exerted when there is a greater, or smaller, surface. As the data plainly shows, the side with more dominoes has greater force exerted on it, but if you shift where the fulcrum is then you can still have equal force on both sides. A larger surface area, as well as force further from the fulcrum, will result in greater total force.
Candy Bar experiment
Description: Take a candy bar of your choice, and tie it to the end of a rubber band chain. Then, applying enough force to cause movement, but not create slack, see how many times it oscillates within a minute.
Candy bar: Milky way
Time: 60 seconds
Oscillations: 130
Explanation: This experiment was an opening into harmonic oscillation. The basic idea to illustrate was that harmonic oscillation occurs whenever a returning force (in this case, the hand movement coupled with elasticity) causes the object to move back and forth.
Steel balls of ramp experiment
Description: Roll steel balls down a ramp, and see how far from the table they land, as well as the time taken to roll DOWN THE RAMP (not the time until it hits the floor). Increase the number of dominoes each time.
Data:
Dominoes Time Distance from table
3 1.9 sec 17 cm
4 1.7 sec 19.5 cm
5 1.5 sec 23.5 cm
Constant: 0.4 seconds for the ball to hit the ground (constant, as vertical and horizontal acceleration are separate, thus vertical acceleration is identical once leaving the ramp)
Explanation: One of the first experiments we did, illustrating basic ideas of acceleration and velocity. Of course, the most basic thing illustrated here is quite simple. When the ramp has a steeper incline, the velocity increases. However, we also see the fact that horizontal acceleration does NOT influence vertical acceleration.
Rubber band experiment
Description: Take a rubber band chain and measure its length. Then add a domino to the bottom, measure the length again. Repeat with more dominoes.
Data:
Base length: 48 cm
Length of chain Number of dominoes
51 cm 1
52 cm 2
54 cm 3
Explanation: This was done to display tension, as well as work as a force meter for later experiments (if memory serves). The largest difference in length occurs from the initial domino, with additional weight not adding as much length as the initial add-on. This means that as the rubber band chain stretches, it becomes more resistant to being stretched.
Rotation/momentum experiment
Description: place a long piece of Styrofoam on a point of rotation. After putting one domino on each end, spin it and see many rotations it has. Then push the dominoes closer to the center and try again.
Data: I was unable to collect exact data, as spinning it without either A) spinning off the fulcrum, or B) Never going further than ¼ of a revolution, proved impossible.
Explanation: I was able to figure out the basic idea from other’s data. When the dominoes were on the outside, rotations increased. As the dominos were moved closer together, the rotations decreased. This means that force dispersed more slowly when the dominoes were on the outside.
Bouncing marble Experiment
Description: Take a small marble, and drop it from a predetermined height. Measure the distance it bounces back up. Repeat this with three different heights. After this, do the exact same thing with a larger marble.
Data:
Large marble
Drop distance Bounce distance (multiple trials)
20 cm 9 cm, 10 cm, 10 cm, 10 cm
40 cm 21 cm, 23 cm
60 cm 30 cm, 29 cm, 30 cm, 30 cm
Small marble
Drop distance Bounce distance (multiple trials)
20 cm 15 cm, 14 cm, 15 cm
40 cm 28 cm, 29 cm, 29 cm
60 cm 32 cm, 32 cm
Explanation: This demonstrates a transfer of energy. The larger marble hits the ground with more force, so it loses more energy upon collision, which is why the smaller marble consistently bounces higher.
Known missing experiments
-Steel ball down ramp, collision with marble
I need to repeat this one, and measure where the steel ball hits after collision, not just the marble.
-Three rubber bands
I believe I didn’t make it to class when we did this particular experiment, as such, I have no idea what it entails or what it is for.
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Check the 111130 Class Notes regarding other experiments for which you might or might not have data.
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