A mass of 10 kg is at a point A on a table. It is moved to a point B. If the line joining A and B is horizontal, what is the work done on the object by the gravitational force? Explain your answer.

The potential energy of a freely falling object decreases progressively. Does this violate the law of conservation of energy? Why?

Does the transfer of energy take place when you push a huge rock with all your might and fail to move it? Where is the energy you spend going?

A certain household has consumed 250 units of energy during a month. How much energy is this in joules?