course Phy 202
6/13 315pm
Experiment kinmodel_03: Equipartition of energy and the direction of disorder to (increasing or decreasing)Observe the first several seconds of the simulation at the 'slow' default speed. You will see how the particles initially are all moving in or very close to the x direction, with little or no y component. Note the x and y kinetic energies, displayed near the top of the screen.
• Observe what happens to the directions of motion of the particles as they start colliding.
As the particles start colliding, they tend to move more in the y direction than in the x direction.
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• Observe what happens to the x and y kinetic energies.
As the particle start colliding, the x energies decrease and the y kinetic energies increase.
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• Is the system more organized at the beginning of the simulation or after a couple of minutes?
The system is definitely more organized at the beginning of the simulation. The collisions tend to increase the randomness.
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• If the x and y kinetic energies were averaged for 100 years, starting a few minutes after the simulation began, which do you think would be greater?
I think the averages would be about the same. At the beginning of the simulation, the x energies are decreasing while the y energies are increasing, but it will come to a point where the y energies will start to decrease and the x energies will increase, and then it will cycle over and over.
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Run the simulation in this manner several times, and each time determine how long it takes before the total y kinetic energy is first greater than the total x kinetic energy. Report your results.
I ran the simulation on the slow default setting a total of 5 times. On average, it took about 3 minutes for the y kinetic energy to overtake the x kinetic energy.
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Now take some data:
• Running at the fastest default speed, stop the simulation with the pause/break key every few seconds, keeping your eyes closed for at least 2 seconds before stopping the motion.
• Write down the x and y kinetic energies each time.
• Do this at least 30 times.
• Find the average of all of your x and all your y kinetic energies.
• Do you believe the difference in the averages is significant, in that the direction that has the higher average will always tend to have the higher average every time the simulation is run?
After 33 time captures, the average of my x energies is 546.8, and the average of my y energies is 503.3. I do not think that the difference is significant in that the x average will always be higher, especially because many times during the experiment the y energy was higher than the x energy. Over a longer time, I think that the averages will tend to be pretty close to each other.
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&#Good work. Let me know if you have questions. &#
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