Question

Frictional force between two bodies:

• A. adds the motion between the bodies
• B. opposes relative motion between contact surfaces of the bodies
• C. sometimes helps and sometimes opposes the relative motion
• D. increases the relative velocity between the bodies

Answer 1

The correct option is B opposes relative motion between contact surfaces of the bodies

Friction always opposes the relative motion between the two contact surfaces. In result it can either increase or decrease the velocity of the bodies.