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course Phy 202
Nov. 14, 2010 6:26pm
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.
***The motion of the particles is very sparatic as they begin to collide. It seems that the order decreases and the particles go every which way.***
• Observe what happens to the x and y kinetic energies.
***The KEx and KEy fluctuate throughout. When one enegy goes up the other energy goes down. ***
• Is the system more organized at the beginning of the simulation or after a couple of minutes?
***At the beginning***
• 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?
***The KEy would probably be greater because its values seem to be higher than the values of KEx most of the time. ***
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.
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.
x vs yvalues
407.2, 365
355.1, 403.7
347.3, 358.2
288.5, 473.8
503.2, 276.2
324.8, 426.9
310.7, 446.1
363.9, 392.9
393.1, 371.6
414.6, 329.4
306.2, 468.6
451.3, 282.0
288.8, 477.5
227.1, 320.3
386.4, 338.2
399.4, 282.9
375.9, 329.0
307.0, 422.2
432.4, 250.7
478.5, 279.1
404.4, 348.6
423.7, 329.4
458.2, 304.0
410.1, 369.6
354.3, 401.8
298.7, 454.9
344.8, 360.7
405.2, 336.9
231.6, 507.1
283.8, 480.5
• Do this at least 30 times.
• Find the average of all your x and all your y kinetic energies.
***Average of x= 365.94 Average of y= 372.93***
• 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?
***The averages are very close with only a difference of 6.99. It seems that the KEx average could fluctuate enough to be at least 6.99 higher than the KEy average. So, no I do not think that KEy will always be greater each time it is run.
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&#Your work looks very good. Let me know if you have any questions. &#
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