What is the amount of work done in the following cases?Justify your answer by giving appropiate reason
a) by an electron revolving in a circular orbit of radiusr around a nucleus.
b) By the force of gravity when a stone of mass m is dropped from the top of a multi storeyed building of height h
(a) Work done by electron in a complete rotation is zero because displacement of electron is zero.
(b) Work done by the force of gravity = force * displacement in the direction of force
= mg *h
=mgh