Matt shows me Newton's Cradle
Newton's cradle consists of 5 metal balls hanging next to each other and when you swing one ball at the line of other 4, it will cause the ball on the other end to swing out and swing back in which pushes your first ball back out and back in, continuing the cycle.
It shows the principle that when two objects collide, the total momentum of the objects before the collision is equal to the total momentum of the objects after the collision.
Basially when the first ball collides with the second, the first ball stops, and its momentum is transferred to the second ball which passes it on to the third, then the fourth, until it reaches the very last ball, pushing it out so swings into the air.
Not only is this experiment fun to watch, but the clicking sound of the balls hitting each other is quite theraputic too.