Which statement best defines friction?

Which statement best defines friction?

• A. Friction is the energy produced by rubbing
• B. Friction is the force that holds objects together
• C. Friction is the resistance that occurs when two surfaces rub against each other, slowing or stopping motion
• D. Friction is the energy transferred from one object to another

Answer: (C)

Friction is the resistance that happens when two surfaces rub against each other, slowing or stopping motion. It occurs because the roughness of the surfaces catches or grips as they slide, and the more they press together, the stronger that grip can be. You can feel it when you push a book across a desk or when you rub your hands together—the motion slows and energy is transformed into heat. Friction is a force that resists motion and can change how fast something moves, which is why brakes slow a car or why a sled doesn’t glide forever on a rough surface. The other ideas aren’t right because friction isn’t energy produced by rubbing, isn’t the force that holds objects together, and isn’t simply energy being transferred from one object to another.

Friction is the resistance that happens when two surfaces rub against each other, slowing or stopping motion. It occurs because the roughness of the surfaces catches or grips as they slide, and the more they press together, the stronger that grip can be. You can feel it when you push a book across a desk or when you rub your hands together—the motion slows and energy is transformed into heat. Friction is a force that resists motion and can change how fast something moves, which is why brakes slow a car or why a sled doesn’t glide forever on a rough surface. The other ideas aren’t right because friction isn’t energy produced by rubbing, isn’t the force that holds objects together, and isn’t simply energy being transferred from one object to another.