A molecular explanation of pressure

Applet by Fu-Kwun Hwang

This java applet shows a microscopic model for an ideal gas. The pressure that a gas exerts on the walls of its container is a consequence of the collisions of the gas molecules with the walls. In this model:

  1. The molecules obey Newton's law of motion.
  2. The molecules move in all direction with equal probability.
  3. There are no interactions (collisions) between molecules.
  4. The molecules undergo elastic collisions with the walls.

You can change the following parameters:

  1. N: Total number of molecules
  2. P: The pressure of the system
  3. v: The velocity of each molecules
  4. The width of the container (Click near the boundary and Drag the mouse)

The volume of the container is adjusted automatically according to the above parameters.

The animation is suspended when you press the mouse button. It is resumed when you release the button.

Try to find out the relations between:

  1. Total number of molecules N and the volume V
  2. The pressure of the system P and the volume V
  3. The velocity of the molecules v and the volume V