Newton's pendulum is a wonderful gift that demonstrates the laws of physics - the laws of conservation of momentum and energy. When one ball is pulled back and released, it will hit the others and the last ball will bounce to almost the same height. This is because the collisions between the balls are elastic and their kinetic energy and momentum is conserved. Technical specifications: Made of high quality materials Perfect for a gift They can be used to decorate a table at work or at home It has a solid foundation A pendulum has 5 balls It provides a working law of physics Dimensions:Height: 15cm Base length: 20cm Base width: 15cm Ball diameter: 1.8 cm