A sphere of a radius r cm falls from rest in a viscous liquid. Head is produced due to viscous force. The rate of production of heat when the sphere attians its terminal velocity is proportional to …..

Options

A. `r^(2)`
B. `r^(3)`
C. `r^(4)`
D. `r^(5)`

Answer

D

Explanation

Rate of heat production=F.V,
`=6pietarvxxv=6pietarv^(2)`
`[v prop r^(2)]` Terminal velocity `prop r^(5)`