$A$ ball rises to the surface at a constant velocity in a liquid whose density is $4$ times greater than that of the material of the ball. The ratio of the force of friction acting on the rising ball to its weight is

$A$ spherical body of radius $r$ and density $\sigma$ falls freely through a viscous liquid having density $\rho$ and viscosity $\eta$ and attains a terminal velocity $v_0$. The estimated maximum error in the quantity $\eta$ is: (Ignore errors associated with $\sigma, \rho$ and $g$, gravitational acceleration)

We have three beakers $A, B$,and $C$ containing glycerine,water,and kerosene respectively. They are stirred vigorously and placed on a table. The liquid which comes to rest at the earliest is

$Assertion :$ Falling raindrops acquire a terminal velocity.
$Reason :$ $A$ constant force in the direction of motion and a velocity dependent force opposite to the direction of motion,always result in the acquisition of terminal velocity.

$n$ small drops of the same size fall through air with a constant terminal velocity of $5 \ cm/s$. If they coalesce to form a single big drop,what is the terminal velocity of the big drop?

What is the relation between poise and decapoise?