This Contest teaches the meaning of displacement as well as energy.
Students gain some insight for designing and actual building with tools.
Spring loaded small size Victor brand mouse trap. Size and number of rubber bands are teacher's choice for each student. Some small prizes. The mousetrap may be modified in any way you wish as long as all the energy delivered to the car comes from the original components of the mousetrap and the rubber bands. The car must consist of one piece which travels as a unit without external influences.