Question

Ans with complete explaination-Q when speed of a bicycle is increasing on a horizontal road, the force of friction exerted by the ground on the wheels is- 1)In the forward direction on the front wheel and in the backward direction on the back wheel 2)in the backward direction on the front wheel and in the forward direction on the back wheel 3)in the backward direction on both the wheels 4) in the forward direction on both the wheels

Answer 1

the answer is (3) in the backward direction on both the wheels . 
reason ,
since we all know friction always opposes motion and the wheel is moving in forward direction with increasing speed therefore the frictional force will act on opposite side ( backward direction ) on both the wheels . 
       i hope that it will help u ..........................^_^