Week 3 Materials

Day 1

1. Goal: to understand some of the other parameters that affect the particle motion in the gas properties simulation
2. With gravity turned OFF, put 50 particles in the box at a temperature of 300K, and record the temperature (you will have to wait a few moments until the particles have spread out, and you will still see the pressure changing -- write down the pressure number that seems to be in the middle of the range of variation)

Reset the simulation, then put in 100 particles at a temperature of 300K, record the pressure again.

Repeat with particle numbers 50, 100, 150, 200, 300, 400, 500. Graph the results.

What does this graph mean?

3. Use the "Advanced Options" button to change the temperature at which new particles are injected into the box. Set the temperature to 200. Repeat all the measurements you did in number 2.
4. Use the Advanced Options button to change the temperature at which new particles are injected into the box -- set the temperature to 400. Repeat all the measurements you did in 2.
5. If there is still time remaining, repeat all of the above one more time with the volume of the box cut in half, and then again with the volume of the box doubled.

Make graphs for all of these measurements, and answer:

How does particle number affect the pressure?

How does temperature affect the pressure?

How does volume affect the pressure?

Day 2/3

1. We've been manipulating or measuring 4 different variables in this simulation, Pressure, Temperature, Number of particles, and Volume (P, T, N, V). Potentially each one of these could be proportional to each of the others:

2. Each one of these potential proportions constitutes a claim, ie, "I claim that \(P \propto N\), the Pressure is proportional to the Number of particles". What is the evidence for this claim? The graphs we've been making. Every one of them gives a straight line relationship, as the number of particles increases, the pressure increases by the same proportion. So \(P \propto N\). Does this make sense? Can you explain why that makes sense? For every one of the possible proportionalities, write out the claim, write the evidence that supports or refutes it, and write an explanation of why it makes sense.

Day 4

1. Quiz 2 on gas property and temperature concepts.