It is made of high quality plastic and strong steel balls, durable and reliable, and can be used for a long time.Nylon string is tough and flexible, which is not easy to break and can ensure uniform force.Solid steel ball, good vertical sense, strong force when stressed.Pull back one or more of the balance balls, release them and the same number of balls will swing up on the opposite side.Usually, when under normal circumstances, because different force and environment, the swing time will be different. The balance balls continue in perpetual motion for only 15 seconds due to the resistance of the air and friction.Not only demonstrates a pendulum, but also shows the laws about conservation of momentum and energy. Perfect educational toy to embrace the story and the mystery of science.It an make people concentrate and then gradually relax, are great for psychology, science and physics classrooms.By playing this newtons cradle balls, explore significant values of physics, inspire us to better learn and understand the Newton’s laws of motion.
