A block of mass'm' is placed on floor of a lift which is rough. The coefficient of friction between the block and the floor is mu . When the lift falls freely, the block is pulled horizontally on the lift floor. The force of friction is

A block of mass'm' is placed on floor of a lift which is rough. The co

1.	A block of mass'm' is placed on floor of a lift which is rough. The coefficient of friction between the block and the floor is mu . When the lift falls freely, the block is pulled horizontally on the lift floor. The force of friction is
Answer» `MU MG ` zero `1/2 mu mg ` `2 mu mg ` ANSWER :B