Answer: 1. It always acts in the direction opposite to the direction of motion. 2. It's magnitude is equal to that of the force trying to set the object in motion only until it starts to move.
Explanation: Properties of frictional forces:
1. Frictional force always acts parallel to two planes in contact with each other and in a direction opposite to that of relative motion of the two bodies. 2. Frictional forces are caused due to intermolecular interactions between the bodies.
