Question

A cubical vessel of height 1 m is full of water. What is the amount of work done is pumping water out of the vessel? Take g = 10ms–2 

Solution

Correct option is

5000 J

 

Side of the cube l = 1 m. Base area of the cubical vessel = l2. Mass of water contained in a height . Weight of this water . Therefore, work done in pumping out water up to a height x is

          

Therefore, total work done in pumping out water up to a height l is  

          

               

               

               

               = 5000 J

SIMILAR QUESTIONS

Q1

A tank with a square base of area 2.0 m2 is divided into two compartments by a vertical partition in the middle. There is a small hinged door of face area 20 cm2 at the bottom of the partition. Water is filled in one compartment and an acid of relative density 1.5 in the other, both to a height of 4 m. If g = 10 ms–2, the force necessary to keep to door closed is  

Q2

A cubical block of steel of each side equal to l is floating on mercury in a vessel. The densities of steel and mercury are  and . The height of the block above the mercury level is given by   

Q3

A spring balance reads 10 kg when a bucket of water is suspended from it. What will be the reading of the balance when an iron piece of mass 7.2 kg suspended by a string is immersed with half its volume inside the water in the bucket? Relative density of iron is 7.2.  

Q4

A vessel contains oil of density 0.8 gcm–3 floating over mercury of density 13.6 gcm–3. A homogeneous sphere floats with half its volume immersed in mercury and the other half in oil. The density of the sphere in gcm–3 is 

Q5

A body floats in water with 40% of its volume outside water. When the same body floats in oil, 60% of its volume remains outside oil. The relative density of oil is  

Q6

The relative density of ice is 0.9 and that of sea water is 1.125. What fraction of the whole volume of an iceberg appears above the surface of the sea?

Q7

A common hydrometer has a uniform stem graduated downwards from 0, 1, 2, ….. up to 10. When floating in pure water it reads 0 and in a liquid of relative density 1.5, it reads 10. What is the relative density of a liquid in which it reads 5?

Q8

A piece of ice, with a stone frozen inside it, is floating in water contained in a beaker. When the ice melts, the level of water in the beaker

Q9

The dimensions of viscosity in terms of M, L and T are

Q10

The dimensions of Reynold’s number are