# Important questions Physics class XI Mechanics of fluids

Mechanics of fluids

Q. 1. A swimmer is swimming at a depth of 10m inside water. Calculate the absolute and gauge pressure that he will experience.

Q. 2. A trough is filled with mercury and a pipe is immersed in it such that mercury rises in the pipe. Find the height upto which mercury rises.

Q. 3. In a hydraulic press, the area of wider piston in 10m and that of the smaller piston is 10cm. A force of 100N is applied on the smaller piston. Find the force that the wider piston will exert

Q. 4. In a hydraulic lift with A=10m and a = 1cm, a car of 1000Kg is kept on the bigger piston. Find the weight that should be kept on the smaller piston to lift the car.

Q. 5. Show that a cyclender whose density is greater than that of water will never float in water.

Q. 6. A cyclender of radius 10cm, length 10m and density 500Kg/m is floating in water. Find

1. Height of cyclender inside water
2. Volume of cyclender inside water
3. Upthrust acting on the cyclender
4. Buoyant force acting on the cyclender
5. Apparent weight

Q. 7. A film of soap solution is extended from 10*10cm to 20*20cm. The surface tension of the solution is 50 dynes/cm. Find the amount of work done in this process and the surface energy of the film.

Q. 8. A container is divided into 2 compartments and contains water in the left and benzene in the right side. A movable door exists as shown. Find the ratio of height of the 2 liquids if the door should remain closed. Density of benzene = 5gm/cc

Q. 9. A cube of side 10cm is floating in a liquid of density 2gm/cc . The mass of the cube is 1000gms. Find the height of the cube outside water. How much force should be applied on top of the cube so as to fully immerse it.

Q. 10. Explain the following

1. Pascal's law
3. Archimedes principle
4. Reynolds number
5. Stoke's law

Q. 11. An oil drop is put on the surface of cold water. Explain what will happen. Also explain what would have happened had the water been hot.

Q. 12. Explain Bernoulli’s principle and derive the corresponding Bernoulli’s equation.

Q. 13. Briefly explain the cleansing action of detergents

Q. 14. What is viscosity? A metal plate of area 5m2 rests on a liquid film of thickness 5mm. A force of 100N pulls the plate and it moves with a constant velocity of 2m/s. Find the coeff of viscosity of the liquid.

Q. 15. Water is stored in an overhead tank at a height of 10m. Find the velocity of water coming out of a tap located at the ground level.

Q. 16. State the units and dimensions of the following quantities

1. Coeff of viscosity
2. Reynold number
3. Surface Tension
4. Pressure
5. Density
more chapters below :

1.
Mechanics of fluids
2.
Mechanics
3.
Gravitation
4.
Rotational Motion

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