| Ground Element: Place up to three ground elements anywhere in the simulation window. Any falling body that strikes a ground element stops completely (the collision is inelastic). The body's kinetic energy is converted into heat, thermal energy, the sound of the collision, or into reshaping the object (for example, a round object that is squashed flat by the collision with the ground). View this energy conversion using the energy changes bar tool. Bodies cannot move horizontally on ground elements. With the Select tool, you can resize ground elements.