A person is holding a suitcase and moving on a horizontal platform. Is he doing any work?

A coolie carrying a load on his head and moving on a frictionless horizontal platform does no work. Explain the reason why.

A motor car is moving with a constant speed . Is the car engine doing any work?

Is a person doing any work by holding a suitcase ?

A person is holding a bucket by applying a force of 10 N. He moves a horizontal distance of 5 m and then climbs up a vertical distance of 10 m. Find the total work done him.

A amn rowing a boat upstream is at rest with respect to shore. (a) Is he doing any work ? (b) If he stope rowing and moves down with the stream, is any work being done on him ?