Question

Work done by a static friction:

• A. Can be positive
• B. Can be negative
• C. Can be zero
• D. All of these

Answer 1

The correct option is D All of these

When external force is applied on body and body is not moving relative to surface then static friction comes into oppose the the external force.

In classical theory, energy is dependent upon frame of reference.

So depending upon frame of observation and the direction of the friction acting, work done by a static friction can be $-ve,+ve,0$.