Newton's Cradle

How It Works

Newton’s Cradle demonstrates the conservation of momentum and energy. When you pull back one ball and release it, the force transfers through the stationary balls and launches the ball on the opposite end.

Try this:

• Pull back one ball — what happens?
• Pull back two balls — how does the response change?
• Why don’t the middle balls move?

The Physics: This demonstrates Newton’s Third Law (action-reaction) and the conservation of both momentum and kinetic energy in elastic collisions.