1N30.10-Newton’s Cradle


Video: Watch this demo

Instructor’s video

Description: This demonstration shows the conservation of energy and linear momentum for multiple collisions.
Each ball has an equal weight and equal size.


  • Newton’s Cradle

Setup Procedure:

  1. Make sure all the balls are lined up.

Demonstration Procedure:

  1. Explain how the balls are connected with strings.
  2. Pull one ball up and let it go, note that only one ball leaves the other side each time. This is counter intuitive for some students.
  3. Stop the cradle and now pull up to balls together. Note again that two balls leave the other side. This, again, is counter intuitive for some students.
  4. Repeat this with pulling up 3, 4, and 5 balls.
  5. You may also do more complicated things like lifting up 2 balls on one side, and 4 balls on the other, and dropping them at the same time.