Question

When a moving car encounters a patch of ice the brakes are applied. Why is it desirable to keep the wheels rolling on the ice without locking up?​

Answer 1

Static friction exists if the wheels keep rolling on the ice without locking up, resulting in maximum braking force. However, if the wheels lock up then kinetic friction takes over since there is relative slipping between wheel andice. This reduces the braking force and the car takes longer to stop.

Answer 2

Friction exists if the wheels keep rolling on the ice without locking up, resulting in maximumm braking force. However, if the wheels lock up then kinetic friction takes over since there is relative slipping between wheel andice. This reduces the braking force and the car takes longer to stop.