Mechanical properties of fluids practice · Medium

The terminal speed of a sphere of gold $\left( {\mathrm{density} = 19.5\mathrm{kg}{\mathrm{m}^{ - 3}}} \right)$ is $0.2\mathrm{m}{\mathrm{s}^{ - 1}}$ in a viscous liquid $\left( {\mathrm{density} = 1.5\mathrm{kg}{\mathrm{m}^{ - 3}}} \right)$. Then the terminal speed of a sphere of silver $\left( {\mathrm{density} = 10.5\mathrm{kg}{\mathrm{m}^{ - 3}}} \right)$ of the same size in the same liquid is

A large tank is filled with water to a height $H$. A small hole is made at the base of the tank. It takes ${T_1}$ time to decrease the height of water to $\frac{H}{\eta }\left( {\eta > 1} \right):$ and it takes ${T_2}$ time to take out the rest of water. If ${T_1} = {T_2}$, then the value of $\eta$ is

$10 \mathrm{~min}$ are taken to empty a rectangular vessel of height $h$ through an orifice in its bottom. How much time will it take to be emptied the vessel when half filled?

Dimensions of coefficient of viscosity are

Why the blood pressure in humans is greater at the feet than at the brain:

An aeroplane of mass $3 \times 10^4 \mathrm{~kg}$ and total wing area $120 \mathrm{~m}^2$ is in level flight at some height. The difference in pressure between upper and lower surfaces in kilopascal is $\left(g=10 \mathrm{~m} / \mathrm{s}^2\right)$

Ice pieces are floating in beaker A containing water also in a beaker B containing miscible liquid of specific gravity 1.2. When ice melts, the level of

Bernoulli’s principle is not involved in the working/explanation of

Water rises in plant fibres due to

Assertion: A rain drop after falling through some height attains a constant velocity.
Reason: At constant velocity, the viscous drag is just equal to its weight.

A large ship can float but a steel needle sinks because of

Typical silt(hard mud) particle of radius $20\mathrm{\mu m}$ is on the top of lake water, its density is $2000\mathrm{kg}{\mathrm{m}^{ - 3}}$ and the viscosity of lake water is 1.0 mPa, density is $1000\mathrm{kg}{\mathrm{m}^{ - 3}}$. If the lake is still(has no internal fluid motion). The terminal speed with which the particle hits the bottom of the lake is ………. $\mathrm{mm}{\mathrm{s}^{ - 1}}$

A piston of cross-sectional area $100 \mathrm{~cm}^2$ is used in a hydraulic pressure to exert a force of $10^7$ dyne on the water. The cross-sectional area of the other piston which supports an object having a mass of $2000 \mathrm{~kg}$ is

Why the dam of water reservoir is thick at the bottom

Work $W$ is required to form a bubbles of volume $V$ from a given solution. What amount of work is required to be done to form a bubble of volume $2V$ ?

Assertion: A solid sphere placed in the fluid under high pressure is compressed uniformly on all sides.
Reason: The volume of solid sphere will decrease with change of its geometrical shape.

A cubical block is floating in a liquid with half of its volume immersed in the liquid. When the whole system accelerates upwards with acceleration of $g / 3$, the fraction of volume immersed in the liquid will be

The surface tension of soap solution is $0.03\mathrm{N}{\mathrm{m}^{ - 1}}$. the work done in blowing to from a soap bubble of surface area $40\mathrm{c}{\mathrm{m}^2},\left( {\mathrm{in J}} \right),\mathrm{is}$

With the increase in temperature viscosity of a liquid -

Assertion:- Under steady flow the velocity of the particle of fluid is not constant at a point.
Reason:- Ideal fluids are compressible.

If a glass rod is dipped in pure mercury and removed, then mercury does not stick to the rod. This is because

A cork is submerged in water by a spring attached to the bottom of a bowl. When the bowl is kept in an elevator moving with acceleration downwards, the length of spring

Surface tension of a soap solution is able of 2.0 cm diameter will be

A man is sitting in a boat which is floating in a pond. If the man drink some water from the pond, what will happen to the level of water in the pond?

Two narrow bores of diameter $3.0 \mathrm{~mm}$ and $6.0 \mathrm{~mm}$ are joined together to form a U-tube open at both ends. If the U-tube contains water, what is the difference in its levels in the two limbs of the tube? Surface tension of water at the temperature of the experiment is $7.3 \times 10^{-2} \mathrm{~N} / \mathrm{m}$. Take the angle of contact to be zero and density of water to be $1.0 \times 10^3 \mathrm{~kg} / \mathrm{m}^3$. (take, $g=9.8 \mathrm{~m} / \mathrm{s}^2$).

Two drops of the same radius are falling through air with a steady velocity of $5cm$ per sec. If the two drops coalesce, the terminal velocity would be

Terminal velocity of a small sized spherical body having radius $r$ falling vertically in a viscous medium having coefficient of viscosity $\eta$ depends on radius of body and coefficient of viscosity as

A hydraulic lift is designed such that cross sectional area of its arms are $5 \mathrm{~cm}^2 \, \& \, 10 \mathrm{~m}^2$. Find the force applied by mechanic on smaller area in order to lift a car of $5000 \mathrm{~kg}?$

A denotes the area to the right on the cube $h$ the depth of an orifice of area of cross-section$A$, below the liquid surface. The velocity of the liquid flowing through the orifice is

Aerofils are so designed that the speed of air