Question

Friction

• A. promotes motion
• B. opposes motion
• C. acts in the direction of motion
• D. is always a nuisance

Answer 1

The correct option is B

opposes motion

1. Frictional forces come into play when there is relative motion between two surfaces i.e. when one surface moves relative to the other surface, friction opposes this motion.
2. Friction always acts to oppose any relative motion between surfaces.
3. For a simple example: a book resting on a flat table, the frictional force is zero.
4. If we push with a 1 N force, a 1 N frictional force opposes us

Hence, Friction opposes motion.