. A rain drop of radius 2 mm falls from a height
a height of 500 m above the ground. It falls with decreasing acceleration (due to viscous resistance of the air) until at half its original height,
it attains its maximum (terminal) speed and moves with uniform speed thereafter.
What is the work done by the gravitational force on the drop in the first and second half of its journey ?
What is the work done by the resistive force in the entire journey if its speed on touching the ground is 10ms-10
Given data, the radius of drop is r=2mm=2×10-3m
Water density is p=103kgm-3
Height of drop is s=500m
Hence, the work done by the resistive force in the entire journey is -0.162 j.