Explain how maximum static friction is called limiting friction .

Explanation

Let a heavy wooden box be placed on a floor, it being pushed by a person. The static frictional force developed between the wooden box and floor balances the force applied in pushing the box. If two persons try to push it the box does not move as the static frictional force increases in order to balance the force of pushing it. If the pushing force is further increased, at one stage, the static frictional force reaches a maximum value at which it cannot increase any further. This maximum value of static frictional force is called limiting friction. If the applied force on the wooden box is more than limiting friction, then the box starts moving.