Specifications: These Collision Balls are used for to prove the theory that states that ?the applied force will balance with the reaction force?. When one ball collides with another, the other ball on the opposite side will bounce up. When ball no.2 ,3 ,4 is released, it will be reflected as well. These ?Collision balls? are used for the study of the theory of Collisions and the theory of momentum conservation energy. This set consists of 5 metal balls hung close to each other in a straight line. It is attached to a rectangular base of dimensions 40x40x10 cm. It is made of MDF wood, closed with Formica plastic.