Ke/pe Vehicle Help!!! we have to construct a vehicle for physics class that can travel the greatest distance possible. the energy must be stored "in" the vehicle as potential energy, and must have a 'rolling' aspect. we cannot use any chemical reactions or slingshot methods. it must travel atleast 5 meters. i have absolutely no idea what to do. some people have told me something about using a folgers coffee can and putting a rod through it, but i'm still so confused. any ideas and how to construct it would save my life. and my grade!