How does friction affect moving objects?

How does friction affect moving objects?

• A. It speeds them up and adds energy.
• B. It changes their direction without slowing them.
• C. It slows them down and converts some kinetic energy to heat.
• D. It has no effect.

Answer: (C)

Friction is a force that acts between surfaces that rub together and it points opposite to the direction the object is moving. Because of this, friction slows the object down. The energy the moving object has (kinetic energy) goes partly into heat, warming the surfaces—like brakes getting warm or hands rubbing together to warm up. If there were no friction, an object would keep moving at the same speed once it started. The idea that friction speeds things up isn’t right because friction takes energy away and turns it into heat, not into more motion.

Friction is a force that acts between surfaces that rub together and it points opposite to the direction the object is moving. Because of this, friction slows the object down. The energy the moving object has (kinetic energy) goes partly into heat, warming the surfaces—like brakes getting warm or hands rubbing together to warm up. If there were no friction, an object would keep moving at the same speed once it started. The idea that friction speeds things up isn’t right because friction takes energy away and turns it into heat, not into more motion.