Embibe Experts Solutions for Chapter: Viscosity and Surface Tension, Exercise 2: Exercise-2

Water filled in an empty tank of area $10 A$ through a tap of cross sectional area $A.$The speed of water flowing out of tap is given by $v ( \mathrm{m}/\mathrm{s})=10\left(1-\sin \frac{\mathrm{\pi }}{30}\mathrm{t}\right)$ where $\text{'}t\text{'}$ is in seconds. The height of water level from the bottom of the tank at $t=15$ second will be:

Two very wide parallel glass plates are held vertically at a small separation $d,$ and dipped in water. Some water climbs up in the gap between the plates. Let $S$ be the surface tension of water, $P_0=$ atmospheric pressure, $P=$ pressure of water just below the water surface in the region between the plates-

A small ball is left in a viscous liquid form very much height. Correct graph of its velocity with time is :-

A cubical block of side $\text{'}a\text{'}$ and density $\text{'}p\text{'}$ slides over a fixed inclined plane with constant velocity $\text{'}v\text{'}.$ There is a thin film of viscous fluid of thickness $\text{'}t\text{'}$ between the plane and the block. Then the coefficient of viscosity of the thin film will be:

A space $2.5 \mathrm{cm}$ wide between two large plane surfaces is filled with oil. Force required to drag a very thin plate of area $0.5{ \mathrm{m}}^2$ just midway the surfaces at a speed of $0.5 \frac{\mathrm{m}}{\mathrm{s}}$ is $1 \mathrm{N}.$ The coefficient of viscosity in $\mathrm{kg}-\frac{\sec }{{\mathrm{m}}^2}$ is:

A large drop of oil, whose density is less than that of water, floats up through a column of water. Assume that the oil and the water do not mix. The coefficient of viscosity of the oil is ${\eta }_0$ and that of water is ${\eta }_w.$ The velocity of the drop will depend on-

A spherical ball is dropped in a long column of viscous liquid. Which of the following graphs represent the variation of :-

$\left(\mathrm{i}\right)$ Gravitational force with time

$\left(\mathrm{ii}\right)$ Viscous force with time

$\left(\mathrm{iii}\right)$ Net force acting on the ball with time

A small sphere of mass $m$ is dropped from a height. After it has fallen $100 \mathrm{m},$ it has attained its terminal velocity and continues to fall at that speed. The work done by air friction against the sphere during the first $100 \mathrm{m}$ of fall is :-