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प्रश्न
It is easier to lift a heavy stone under water than in air. Explain.
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उत्तर १
It is easier to lift a heavy stone under water than in air because in water, it experiences an upward buoyant force which balances the actual weight of the stone acting downwards. Thus, due to upthrust there is an apparent loss in the weight of the heavy stone, which makes it lighter in water, and hence easy to lift.
उत्तर २
It is easier to lift a heavy stone under water because in water an upthrust acts on the upward direction which reduces the apparent weight of the stone and makes it easy to lift.
संबंधित प्रश्न
When does an object float or sink when placed on the surface of a liquid ?
Distinguish between density and relative density.
Write an expression for the pressure at a point inside a liquid. Explain the meaning of the symbols used.
Explain why a gas bubble released at the bottom of a lake grows in size as it rises to the surface of the lake.
A dam has broader walls at the bottom than at the top. Explain.
State the laws of liquid pressure.
- Calculate the height of a water column which will exert on its base the same pressure as the 70 cm column of mercury. Density of mercury is 13.6 g cm-3.
- Will the height of the water column in part (a) change if the cross-section of the water column is made wider?
What do you understand by the term upthrust of a fluid? Describe an experiment to show its existence.
A body is held inside water contained in a vessel by tying it with a thread to the base of the vessel. Name the three forces that keep the body in equilibrium, and state the direction in which each force acts.
Select the correct option:
When a body is wholly or partially immersed in a liquid, it experiences a buoyant force which is equal to:
