a
(a) Let a heavy wooden box be placed on a hoor, 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. Iftwo persons try to push it the box does not move as the static frictional force increases in order to balance the force ofpushing it: If the pushing force is furce is further increased, at one stage, the static \&ic tional force reaches a maximum value at which it cannot increase any further. This maximum value of static frictional force is called limiting Eiction. If the applied force on the wooden box is more than limiting friction, then the box starts moving.