excercise 6: a fun toy

The toy I choose is the Newton’s cradle. It consists of 5 metal spheres of the same size and weight hanging alinged on the frame. It is shiny and sleek, but I find most people are attracted to it because of its well known behaviour of transmittion of motion between the spheres. Almost everyone knows how to operate it (lift one sphere up then releasing it and expect the one on the other end to go up), but no one seems to know the reason behind it.

this toy practice the law of conservation of momentum and energy. many people misunderstood it to be perpetual motion, when in fact it is not, because the collision between spheres aren’t totally elastic and there are energy lost as forms of heat (friction) and sound.