Question

Frictional force exists in which of the following cases ?

• A. Exists only for moving bodies.
• B. Exists only for bodies which are at rest.
• C. Exists for both moving and non-moving bodies.
• D. None of these

Answer 1

The correct option is C Exists for both moving and non-moving bodies.

Answer is C.
The friction force is the force exerted by a surface as an object moves across it or makes an effort to move across it. Such friction forces are referred to as sliding friction.
Friction forces can also exist when the two surfaces are not sliding across each other. Such friction forces are referred to as static friction.
Hence, frictional forces exists for both moving and non-moving bodies.