Question

It is well known that a raindrop falls under the influence of the downward gravitational force and the opposing resistive force. The latter is known to be proportional to the speed of the drop but is otherwise undetermined. Consider a drop of mass 1.00 g falling from a height 1.00 km. It hits the ground with a speed of 50.0ms‚àí1.What is the work done by the gravitational force

Answer 1

Mass of rain drop ,m = 1.00 g
Initial velocity of rain drop , u = 0 m/s
Final velocity of rain drop , v = 50 m/s
Height , s = 1.0 km = 1000 m
v^2 = u^2 + 2 × a × s
(50)^2 = (0)^2 + 2 × a × (1000)
2500 = 0 + 2 × a × 1000
2 × a = 2.5
a = 1.25 m/s
Work done ,W = Force(F) × Height(s)
W = m × a × s
= 1.00 × 1.25 × 1000
= 1250 J

Answer 2

see the attachment for the answer