Friction

Friction is a force that slows moving things down and turns the moving energy into heat energy. When two things rub together, like your bike tires and the road, friction between them slows you down. There’s also friction in the metal parts of the wheel’s hub – at the center. There’s even friction between the fibers and rubber of the tires themselves as they flex and roll. That’s why you eventually stop rolling when you stop pedaling. Rough things make more friction than smooth things. Rubber shoes on a clean wooden basketball floor create more friction than do hard metal skate blades on smooth ice.

Friction also heats things up. When you rub your hands together, they get warm. You’re making enough friction to feel the heat. Friction takes the energy of your moving hands and turns it into heat energy.

Friction with Bill Nye is a smooth science ride.

The Big Ideas

• Friction is the resistance to motion of things that are touching.
• Friction changes the energy of motion to heat.

Did You Know That?

• Without friction, you couldn’t walk?
• Meteors get burned up in the atmosphere because friction between the air and the rock makes lots of heat?
• Violinists use rosin on their bows to increase the friction between the bow and strings? The friction makes the music.

Books of Science!

• “Be a Kid Physicist” by William R. Wellnitz, Ph.D. Published by TAB Books, 1993.