PhysicsCode 9702
Kinetic theory of gases
What this topic asks you to be able to do
- give the fundamental assumptions on which the kinetic theory of gases rests
- explain how the movement of molecules gives rise to gas pressure, and derive and use pV = 1/3 Nm<c²>, where <c²> is the mean-square speed (a simple model of one-dimensional collisions, extended to three dimensions using 1/3 <c²> = <cx²>, is enough)
- understand that cr.m.s., the root-mean-square speed, is equal to <c²>
- compare pV = 1/3 Nm<c²> with pV = NkT and conclude that a molecule's average translational kinetic energy comes to 2/3 kT, then recall and apply this expression