The terminal speed of a sphere of gold (density = 19.5 kg `m^(-3)`) is 0.2 `ms^(-1)` in a viscous liquid (density = 1.5 kg `m^(-3)`). Then, the terminal speed of a sphere of silver (density = 10.5 kg `m^(-3)`) of the same size in the same liquid is

Options

A. `0.4 ms^(-1)`
B. `0.133 ms^(-1)`
C. `0.1 ms^(-1)`
D. `0.2 ms^(-1)`

Answer

C

Explanation

Terminal speed of spherical body in viscous liquid is given by
`V_(T)=(2r^(2)(rho-sigma)g)/(9eta)`
where `rho=` density of substance of body
and `sigma=` density of liquid