Newton’s Cradle: How does it work?

My dad recently bought this really cool toy by the name of Newton’s cradle. The desk toy has five metal balls positioned as a row and are all hung by strings attached to a metal frame. What makes this toy so cool is what the toy actually DOES. If I was to pull one metal ball from one end, the three balls in the middle don’t move at all, but the ball on the opposite end gets propelled into the air. It then swings back and keeps on doing the same thing again and again. It made me wonder why the three balls in the center didn’t move at all. So I did my research and want to inform you.

Conservation of momentum

The desk toy clearly shows the use of some of the fundamental principles of physics. The conversation of momentum means that when two objects collide, the momentum of the objects right before the collision is the same as the amount of momentum after the collision occurs.

That means that when the ball is dropped from one end and collides with the second ball, the momentum is transferred between all of the balls and is exerted into the ball on the other end. Making it propel into the air.

Conservation of energy

Newton’s law of conservation of energy states that energy isn’t made or destroyed, but changes form. Newton’s cradle shows this perfectly. The ball that has been has potential energy, which changes into kinetic energy making the ball on the other end swing in the air.

Newton’s cradle is really cool. Who knew something that looks so simple could be so complicated? I’ve learnt a little bit more about how physics is applied in different ways and I hope you have as well.

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