A raindrop of mass 3.35 x 105 kg falls vertically at constant speed under the influence of

Question:

A raindrop of mass 3.35 x 10─5 kg falls vertically at constant speed under the influence of gravity and air resistance. Model the drop as a particle. As it falls 100 m, what is the work done on the raindrop (a) by the gravitational force and (b) by air resistance?