What is work done by a force of gravity in the following cases?
(a) Satellite moving around the Earth in a circular orbit of radius 35000 km.
(b) A stone of mass 250 g is thrown up through a height of 2.5 m.
(a) Zero
(b) Given,
mass (m) = 250 g = 0.25 kg
height (h) = 2.5 m
Workdone, W = Fs = mgh = 0.25 × 10 × 2.5 = 6.25 J
W = 625 J