Before we give the main formula of kinetic theory, let us first try and understand the effect of temperature and volume on the number of collisions of the gas molecules with the walls. In the applet below, you can change the temperature and volume with the sliders on the left side. You can also adjust the time for which the simulation runs. The applet counts all collisions and displays the result after the run. By varying temperature and volume and keeping track of the number of collisions, you can get a good feeling of what the main result of kinetic theory will be.