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course Phy 232
6-13-11 about 9:15pm
Preliminary ObservationRun the program kinmodel, accepting all defaults by using the 'Enter' key to answer the prompts on your computer (the computer will then automatically pick the selection with the asterisk) and observe the particles or 'billiard balls' bouncing around the screen and off one another.
• Watch the KEx and KEy values as they change with each collision, representing the total x and y kinetic energies of the particles.
• Watch the 'red' particle for a couple of minutes, estimating the average time between its collisions and its average speed (one of the speeds given near the top of the screen corresponds to that of the 'red' particle--which is it?).
• Watch the 'blue' particle, and speculate on what property of this particle is different from that of the other particles.
• Watch as the 'red' particle sometimes turns yellow. What causes this? What property does the particle have when it is yellow?
• What might the graphs represented at the right of the screen represent?
• Strike the 'S' key to stop the simulation, and if you are done give the appropriate response to the prompt to quit the program. CTRL-ALT-DELETE will also stop the program, but if you're not careful it will reboot your computer so avoid that option if you can.
1: The estimated t_ave between collisions of the red, as best I could see, is less than 1 second. I’m not sure how to tell what the speed of the red ball is, so I’m going to guess as to which # on the screen represents this. Estimated ave speed of the red ball is 5 ( and I’m not sure of the units either).
2: The Blue particle is different in that its mass is greater than the others
3: The red particle changes to a yellow color when it comes into contact with one of the yellow particles and apparently the yellow particle clings to the red for a period of time before being released. I’m not sure of what different property the red particle has when this occurs, I couldn’t tell much difference in the way it acted before or after the encounter with the yellow particle.
4: I’m guessing that the graphs on the side of the screen represent the KE of the x and y movements, with the red being the x and the light blue being the y.
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&#Good responses. Let me know if you have questions. &#