Question

Three situation relayed to work are given below
Pushing an object of mass 10kg across a horizontal floor
Lifting an object to a height of 5m
A boy standing still with an object on his head

In which of the above situation work is not done
In which situation does kinetic energy takes place without a change in potential energy

Answer 1

(A boy standing still with an object on his head) work is not done because there is no displacement
(pushing an object of mass 10 kg across a horizontal floor) kinetic energy takes place without a change in potential energy because kinetic energy is energy of an object due to its movement