During paddling of a bicycle,the force of friction exerted by the ground on the two wheels is such that-

Shaurya Gupta
41 Points
10 years ago

Since the rear wheel rotates by itself (we only paddle to rotate the fron wheel), the friction acts in backward direction which provides torque for the required rotation.But friction acts forward on front wheel as friction acts opp. to the direction of sliding or opposes the relative motion.

Prannoy Mehta
13 Points
7 years ago
I am sorry Shaurav Gupta but the answer provide is wrong. I crossed checked with Arihant Publications past IIT question. It was asked in 1990, for 2 marks. The answer is that the for the front wheel the direction of friction is backward (to the direction of motion) and whereas for the back wheel, it is in the opposite direction, if you have completed Rotational Mechanics, this might be easier to understand.
aarisha
19 Points
4 years ago
the front wheel is moving by itself experiences force f friction in forward direction and force of friction exerted on the rear wheel on the ground is in the forward direction BACK WHEEL----->     &
FRONT WHEEL
Aastha Luthra
44 Points
4 years ago
As the front wheel is not connected to the axle so we cannot rotate it. We can only provide it Linear velocity and hence friction acts in the backward direction to provide torque to the wheel so that it rotates. While in case of the back wheel, when we palepa, the axle rotates and the wheel also rotates due to which frictional force will act in the forward direction to oppose the motion
Siddharth Singh
100 Points
4 years ago
Since the rear wheel rotates by itself (we only paddle to rotate the fron wheel), the friction acts in backward direction which provides torque for the required rotation.But friction acts forward on front wheel as friction acts opp. to the direction of sliding or opposes the relative motion......Thanks