Newton's cradle balance pendulum ball toy is a good practice of physics in action that demonstrates the principles of kinetic energy and conservation of momentum. When one sphere at the end is lifted and released, it strikes the stationary spheres; a force is transmitted through the stationary spheres and pushes the last sphere upward. The device is also known as Newton's balls or Executive Ball Clicker. Based on the law of conservation of momentum and energy conservation, due to resistance reason, newton's cradle will not swing forever. Usually, when under normal circumstances, the balls will swing about 15 seconds. But because of different forces and environments, the swing time will be different.