Question

The terminal velocity of spherical ball of radius a falling through $a$ viscous liquid is proportional to

• A. $ a $
• B. $a^{2}$
• C. $a^{3}$
• D. $a^{-1}$

Answer 1

Answer: (B)

If a spherical body of radius a is dropped in a viscous fluid, it is first accelerated and then its acceleration becomes zero and it attains a constant velocity called terminal velocity.
Terminal velocity, $v=\frac{2}{9} \frac{a^{2}(\rho-\sigma) g}{\eta}$
where $\rho$ is the density of the body, $o$ is the density of fluid and $\eta$ is coefficient of viscosity.