Question

When a bicycle is in motion, the force of friction exerted by the ground on the two wheels is such that it acts
(A) In the backward direction on the front wheel and in the forward direction on the rear wheel.
(B) In the forward direction on the front wheel and in the backward direction on the rear wheel.
(C) In the backward direction on both the front and rear wheels.
(D) In the forward direction on both the front and rear wheels.

Answer 1

The force of friction refers to the force created by two surfaces that touch and slide against each other. The frictional force also works on the bicycle's wheels, front wheel, and rear wheel. Here, rolling friction occurs when bicycle wheels continually spin. Friction opposes the object’s motion.

Complete answer: The rear wheel works in cycling by the force communicated to it by pedaling while the front wheel moves on its own. The force applied by the rear wheel on the ground causes the force of friction to work on it in the forward direction when pedaling a bicycle (like walking). The rotation of the front wheel itself feels friction force in the backward direction (like the rolling of a ball). If pedaling is halted, though, both wheels travel on their own and so feel friction force in a backward direction].
Hence, option (A) is the correct option.

Note: In this question you are asked to find the direction of the front and rear wheel. Here, we apply the concept of frictional force and try to understand how it affects the wheels of bicycles. At last we find that the front wheel of the bicycle is moving in the backward direction and the rear wheel of the bicycle moving in the forward direction.