Force of viscosity acting on a spherical body of radius r moving with velocity v through a fluid of viscosity η is given by

Q. Spherical balls of radius $R$ are falling in a viscous fluid of viscosity $\eta$ with a velocity $v$. The retarding viscous force acting on the spherical ball is:

Q. Spherical balls of radius $R$ are failing in a viscous fluid of viscosity $\eta$ with a velocity $v$. The retarding viscous force acting on the spherical ball is

Q. The viscous force $F$ acting on a rain drop of radius '$a$' falling through air of coefficient of viscosity ${}^{\prime }{\eta }^{\prime }$ with terminal velocity $V$ is given by $F$ $\alpha$ $n^x{a}^y{V}^z$. The values of $x,y$ and $z$ are :

Q. When a small sphere moves at low speed through a fluid, the viscous force $F$, opposing the motion is experimentally found to depend upon the radius $r$, the velocity $v$ of the sphere and the viscosity $\eta$ of the fluid. Expression of force is proportional to
Note: $\left[\eta \right]=\left[M{L}^{-1}{T}^{-1}\right]$

Q. A spherical ball of radius $R$ is falling in a viscous fluid of viscosity $\eta$ with a velocity $v$. The retarding viscous force acting on the spherical ball is: