When a body is moving on a surface, the force of friction is called

Assertion : Friction always opposes the motion. Reason : Whenever one surface moves or tries to move over another surface, the force of friction starts acting on the surfaces.

(A) : Angle of repose is equal to angle of limiting friction. ( R) : When the body is just at the point of motion, the force of friction in this stage is called as limiting friction.

Assertion : Angle of repose is equal to angle of limiting friction. Reason : When the body is just at the point of motion, the force of friction in this stage is called as limiting friction.

Assertion : Angle of repose is equal to angle of limiting friction. Reason : When the body is just at the point of motion, the force of friction in this stage is called as limiting friction.

Assertion : Angle of repose is equal to angle of limiting friction. Reason : When the body is just at the point of motion, the force of friction in this stage is called as limiting friction.

When a body moves on a circular path, the force that acts on the revolving body towards the center is called :

A body of weight 50 N is placed on a smooth surface. If the force required to move the body on the rough surface is 30 N the coefficient of friction is