A small sphere of mass m is drpped from a height. After it has fallen 100m, it has attained its terminal velocity and continues to fall at that speed. Then the modulus of work done.

Options

A. By viscosity of air is lesser in first 100 m than in the second 100 m
B. by buoyancy of air is in first 100 m is equal to that in the second 100 m
C. by viscosity of air is greater in first 100 m than in the second 100 m
D. by buoyancy of air is lesser in first 100 than that in the second 100 m

Answer

A, B

Explanation

Average viscous force over the first 100 m is lesser than that over second 100 m, as viscous force is proportional to v. But buoyancy force of air is constant throughout.