A classic example of momentum in action is Newton's cradle. The metal balls are held next to each other and suspended by strings. When one of the balls on the end is lifted and released to swing into the rest of the balls, the momentum and energy of the first ball are transferred through the line of balls. When this momentum reaches the end ball, it swings upward. When the ball comes down, the process is repeated. At the height of a ball's swing, it reaches a point of maximum gravitational potential energy. Conversely, it is at a point of maximum kinetic energy at the bottom of its swing. This motion can occur a large number of times due to the cradle's efficiency in conserving momentum and energy.
Does Newton's cradle resemble an elastic or inelastic collision?
What causes the balls to slow down? What forces and conditions affect this process?
What would happen when two balls are swung instead of just one? Could you swing more?
Can too many balls be swung? How would you define too many?
If you need more help understanding Newton's Cradle and some of the Phsyics behind it, watch this video!