Question

When a body is rolling without slipping on a rough horizontal surface,the work done by friction is

• A. Always zero
• B. May be zero
• C. Always positive
• D. Always negative

Answer 1

The correct option is A Always zero

• Since work done=force $\times$ displacement.
  
• In case of rolling without slipping ,there is no relative motion between the point of central of the object ans the surface i.e,the displacement of the point of contact of the object is 0.
• Therefore work done is zero.