The simulation shows a gas confined in a cylinder with a movable piston, initially at rest. The atoms strike piston and exert a force on it toward the right. This force causes the piston to move at increasing speed. Note, that the force of gas on the piston and the piston΄s displacement are in the same direction, so the gas does positive work on the piston. Draw attention on the values of the piston΄s kinetic energy and the kinetic energy of the atoms in a cylinder.