Question

A block of mass 1 Kg is placed on a rough floor of lift. The coefficient of friction between the block and the floor is 0.3 when the lift Falls freely the block is pulled horizontally on the floor what will be the force of friction in Newton

Answer 1

The lift falls freely , means gravitational force act on the block must be zero.

As we know ,

       Frictional force is directly proportional to normal reaction act on the body. E.g., friction = μ N

Where μ is coefficient of friction and N is normal reaction acts on the body.

But normal reaction acts on the body = gravitational force acts on the body =0

So, friction force acts on the body = 0