Question

A solid sphere is executing rolling with slipping motion on a rough horizontal surface

• A. the frictional force will always perform a negative work on the sphere
• B. the work done by friction cannot be zero
• C. the angular momentum of the sphere is conserved about its centre of mass
• D. the angular momentum of the sphere is conserved about point of contact

Answer 1

Answer: (A), (B), (D)

The correct options are
A the frictional force will always perform a negative work on the sphere
B the work done by friction cannot be zero
D the angular momentum of the sphere is conserved about point of contact

Friction force will do rotational and translational work in loses of slipping with rolling and sum of this work is non zero. About point of contact net torque by all the forces (normal, weight, and friction) is zero so angular momentum remains conserved about this point.