When a car goes around a circular curve on a horizontal road at constant speed,what force causes it to follow the circular path?
A)the normal force exerted on the car by the road perpendicular to the road
B)the friction force exerted by the road on the car
C)the force that Earth exerts on the car
D)No force causes the car to do this because the car is traveling at constant speed and therefore has no acceleration.

Question

Quizplus · Accepted Answer

The force that causes the car to follow the circular path is the friction force exerted by the road on the car. This force acts towards the center of the circle and provides the necessary centripetal force to keep the car moving in a circular path at a constant speed. The normal force (A) only counters the weight of the car and keeps it from falling through the road. The force of Earth (C) may play a role in determining the weight of the car, but it has no direct effect on the circular motion. Option D is incorrect because a constant speed does not mean absence of acceleration, but in the circular motion, the acceleration changes direction continuously, and hence, the constant speed is maintained.

When a Car Goes Around a Circular Curve on a Horizontal