# First Year Physics Fluid Dynamics The pipe near the lower end of a large water storage tank develops a small leak and a stream of water shoots from it. The top of water in the tank is 15 \mathrm{~m} above the point of leak.(i) With

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##### The pipe near the lower end of a large water storage tank develops a small leak and a stream of water shoots from it. The top of water in the tank is 15 \mathrm{~m} above the point of leak.(i) With what speed does the water rush from the hole?(ii) If the hole has an area of 0.060 \mathrm{~cm}^{2} how much water flows out in one second?

Explain how the swing is produced in a fast moving cricket ball.

For which position will the maximum blood pressure in the body have the smallest value. (a) Standing up right (b) Sitting (c) Lying horizontally (d) Standing on ones head?

What gauge pressure is required in the city mains for a stream flow a fire hose connected to the city mains to reach a vertical height of 15 \mathrm{~m} ?

Explain the difference between laminar flow and turbulent flow.

An airplane wing is designed so that when the speed of the air across the top of the wing is 450 \mathrm{ms}^{-1} the speed of air below the wing is 410 \mathrm{~ms}^{-1} . What is the pressure difference between the top and bottom of the wings? (Density of air =1.29 \mathrm{kgm}^{-3} ).

The radius of the aorta is about 1.0 \mathrm{~cm} and the blood flowing through it has a speed of about 30 \mathrm{cms}^{-1} . Calculate the average speed of the blood in the capillaries using the fact that although each capillary has a diameter of about 8 \times 10^{-4} \mathrm{~cm} there are literally millions of them so that their total cross section is about 2000 \mathrm{~cm}^{2} .

Identify the correct answer. What do you infer from Bernoullis theorem?(i) Where the speed of the fluid is high the pressure will be low.(ii) Where the speed of the fluid is high the pressure is also high.(iii) This theorem is valid only for turbulent flow of the liquid.

State Bernoullis relation for a liquid in motion and describe some of its applications.

Explain the working of a carburetor of a motorcar using Bernoullis principle

What is meant by drag force? What are the factors upon which drag force acting upon a small sphere of radius r moving down through a liquid depend?

Two row boats moving parallel in the same direction are pulled towards each other. Explain.

An airplane design calls for a "lift" due to the net force of the moving air on the wing of about 1000 \mathrm{Nm}^{-2} of wing area. Assume that air flows past the wing of an aircraft with streamline flow. If the speed of flow past the lower wing surface is 160 \mathrm{~ms}^{-1} ? The density of air is 1.29 \mathrm{kgm} and assume maximum thickness of wing be one meter.

In an orbiting space station would the blood pressure in major arteries in the leg ever be greater than the blood pressure in major arteries in the neck?

A tiny water droplet of radius 0.010 \mathrm{~cm} descends through air from a high building. Calculate its terminal velocity. Given that \eta for air =19 \times 10^{-6} \mathrm{~kg} \mathrm{~m}^{-1} \mathrm{~s}^{-1} and density of water \rho=1000 \mathrm{kgm}^{-3} .

An airplane design calls for a "lift" due to the net force of the moving air on the wing of about 1000 \mathrm{Nm}^{-2} of wing area. Assume that air flows past the wing of an aircraft with streamline flow. If the speed of flow past the lower wing surface is 160 \mathrm{~ms}^{-1} ? The density of air is 1.29 \mathrm{kgm}^{-3} and assume maximum thickness of wing be one meter.

Two row boats moving parallel in the same direction are pulled towards each other. Explain.

Explain what do you understand by the term viscosity?

In an orbiting space station would the blood pressure in major arteries in the leg ever be greater than the blood pressure in major arteries in the neck?

For which position will the maximum blood pressure in the body have the smallest value. (a) Standing up right (b) Sitting (c) Lying horizontally (d) Standing on ones head?

An airplane wing is designed so that when the speed of the air across the top of the wing is 450 \mathrm{ms}^{-1} the speed of air below the wing is 410 \mathrm{~ms}^{-1} . What is the pressure difference between the top and bottom of the wings? (Density of air =1.29 \mathrm{kgm}^{-3} ).

A water hose with an internal diameter of 20 \mathrm{~mm} at the outlet discharges 30 \mathrm{~kg} of water in 60s. Calculate the water speed at the outlet. Assume the density of water is 1000 \mathrm{kgm}^{-3} and its flow is steady.

Water flows down hill through a closed vertical funnel. The flow speed at the top is 12.0 \mathrm{cms}^{-1} . The flow speed at the bottom is twice the speed at the top. If the funnel is 40 \mathrm{~cm} long and the pressure at the top is 1.103 \times 10^{5} \mathrm{Nm}^{-2} what is the pressure at the bottom?

Explain the working of a carburetor of a motorcar using Bernoullis principle

Water flows through a hose whose internal diameter is 1 \mathrm{~cm} at a speed of 1 \mathrm{~ms}^{-1} . What should be the diameter of the nozzle if the water is to emerge at 21 \mathrm{~ms}^{-1} ?

How large must a heating duct be if air moving 3.0 \mathrm{~ms}^{-1} along it can replenish the air in a room of 300 \mathrm{~m}^{3} volume every 15 min? Assume the airs density remains constant.

A person is standing near a fast moving train. Is there any danger that he will fall towards it?

A person is standing near a fast moving train. Is there any danger that he will fall towards it?

The radius of the aorta is about 1.0 \mathrm{~cm} and the blood flowing through it has a speed of about 30 \mathrm{cms}^{-1} . Calculate the average speed of the blood in the capillaries using the fact that although each capillary has a diameter of about 8 \times 10^{-4} \mathrm{~cm} there are literally millions of them so that their total cross section is about 2000 \mathrm{~cm}^{2} .