Explanation:
given,
rate of increase of volume of sphere = 25π m³/h
volume at certain time =
calculate the rate of change of surface area = ?
volume of sphere
r³ = 8
r = 2 m
surface are of the sphere
A = 4 π r²
now,
D. Mechanical energy remains unchanged.
Mechanical energy = Potential energy + Kinetic energy
So if potential energy decreases, then kinetic energy must increase so that the system is balanced.