# ^Motion of a body on a fixed rough horizontal surface

**^Motion of a body on a fixed rough horizontal surface **

Suppose a block of mass ‘m’ placed on a rough horizontal plane is pulled by a horizontal force F.

Following are the various possibilities:

- If F = 0, then the frictional force acting on the block will be zero & the block will remain stationary.
- If F < f
_{L}, then the frictional force acting on the block will be equal to F & the block again will remain stationary. - If F = f
_{L}, then the frictional force acting on the block will be equal to f_{L}& the block will be at the verge of motion i.e. about to move. - If F > f
_{L}, then the frictional force acting on the block will be equal to f_{K}& the block will move with acceleration a= f- f_{k }/m in the direction of force applied F.