Question

When speed of a car is increasing, its driving wheels experience:

• A. The force of kinetic friction directed backward
• B. The force of static friction directed backward
• C. The force of kinetic friction directed forward
• D. The force of static friction directed forward

Answer 1

Answer: (D)

The force of static friction directed forward

When speed of a car is increasing, the wheels of the car try to push the ground backwards thereby getting a forward frictional force. The friction in this case is static friction as there is no relative motion between the instantaneous center of rotation and the ground. If there was a relative motion between them kinetic friction would have been used.
Ans: (D)