Help - Skaters and Blocks

The applet shows two skaters pushing off from each other or, alternatively, two blocks that are being forced apart. The applet demonstrates the resulting momenta, speeds, and kinetic energies of the two skaters or blocks.

It is assumed that the surfaces on which the blocks slide or the ice on which the skaters slide exert a negligible amount of friction on the sliding objects. This way, there is no net external force acting on the two systems.

It is assumed that the mass of the expanding gas in the explosion forcing the two blocks apart is negligible. Otherwise, the momentum of the gas cloud might not be zero, causing the momenta of the two blocks to have unequal magnitudes.