Newton's Cradle Desktop ToyWitness the fascinating phenomenon of Newton's Cradle in action! This classic physics toy brings the principles of momentum and conservation of energy to life right before your eyes. Newton's Cradle consists of a series of identical metal balls suspended from a frame. When one of the balls on the end is pulled back and released, it swings forward and strikes the next ball in line. This impact causes the last ball to be propelled into the air, while