Here"s the deal: i"m a high school student interested in momentum and energy conservation> my science projects has enough backround information and what not<Thats not the problem>my actual experiment is proving perpetual motion impossible using a line of marbles>i am going to line up the marbles and drop one into the mess< one pops out the other side< not two with half the speed< thats because kinetic energy must also be conserved and since the number of balls remains consistent, That shows that kinetic energy after the collision cant be more than before the collision> hence no perpetual motion> but how can i use the same principle in a more impressive project? please please please tell me!