Book 3, Question 43
Why Does Rubbing Hands Make Heat?
When you rub your hands together, the rough surfaces grab and slip against each other. That tug-of-war is called friction. Friction turns the energy of your moving hands into heat.
From the book
Page from A Million Whys Book 3
More fun facts
- Friction is a force between two surfaces rubbing against each other.
- When you rub your hands, some of the energy of their movement turns into heat.
- Rubbing hands together on a cold day is an easy way to warm up.
- Long ago, people used the same idea to make fire by rubbing sticks together.
- When there is a lot of friction between moving parts, energy is lost to the surroundings as heat.
- Cyclists tuck in tightly to cut down the rubbing of air against their bodies.
Questions kids ask
How did people make fire by rubbing sticks?
Rubbing sticks makes friction, and friction turns movement into heat. Rub long enough and the wood gets hot enough to catch fire.