Fun Fact Friday: Bouncing balls – Rubber vs. Steel

© ?? ??/Wikimedia Commons

© Takahashi Takashishi/Wikimedia Commons

Did you know that, when dropped from the same height, a hardened steel ball will actually bounce higher than a rubber ball of the same size? It’s true!

When you drop a ball on a surface, it compresses and squashes slightly, before snapping back to its original shape. Since steel snaps back much faster than rubber, the steel ball will bounce higher, especially when dropped on another very hard surface, like steel.

The key is stored energy. Since hardened steel is usually created with carbon, the steel’s natural atomic crystalline tendencies are countered, causing the ball to deform only briefly. This stores a great deal of collision energy in the process, giving the ball its spring.

In addition, a solid glass ball will also bounce higher than a rubber ball, but then the trick is finding a surface hard enough to make the ball bounce, but not hard enough to break it!

Want to learn more about physics? Check out The Physics Tutor: Volume 13: Inelastic and Elastic Collisions on Discovery Education Streaming!

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