A horizontal force is applied to a block initially at rest on a rough horizontal table
PHYSICS · Single correct · CBSE · Physics · Laws of Motion · Laws of Motion
Problem
A horizontal force is applied to a block initially at rest on a rough horizontal table. Which statement correctly describes the frictional force acting on the block as the magnitude of the applied force is slowly increased from zero?
(a) It increases from zero up to a maximum μkN and then suddenly rises further to a constant value μsN once the block starts sliding.
(b) It grows exactly in step with the applied force; even after the block is set in motion the friction continues to equal the applied force.
(c) It increases from zero up to a maximum μsN and then suddenly drops to a constant value μkN once the block starts sliding.
(d) It remains constant and equal to μkN whether the block is at rest or moving.