Eight identical drops of water falling through air with a uniform terminal velocity of $10 \ cm/s$ combine to form a single big drop. The terminal velocity of the big drop will be: (in $cm/s$)

If an air bubble of diameter $2 \text{ mm}$ rises steadily through a liquid of density $2000 \text{ kg/m}^3$ at a rate of $0.5 \text{ cm/s}$, then the coefficient of viscosity of the liquid is . . . . . . $\text{Poise}$. (Take $g = 10 \text{ m/s}^2$)

Two equal drops are falling through air with a steady velocity of $5\, cm/s$. If two drops coalesce to form one drop,then the new terminal velocity will be:

$A$ small metal sphere is falling through a viscous liquid. The variation of velocity $(V)$ with time $(t)$ is shown correctly in which graph?

Which of the following is the incorrect graph for a sphere falling in a viscous liquid? (Given at $t = 0$,velocity $v = 0$ and displacement $x = 0$.)

$A$ ball rises to the surface of a liquid with constant velocity. The density of the liquid is four times the density of the material of the ball. The viscous force of the liquid on the rising ball is greater than the weight of the ball by a factor of