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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
A body while floating sinks deeper in a liquid of low density than in a liquid of high density.
How does the density of a body and that of a liquid determine whether the body will float or sink into that liquid?
The density of water is 1.0 g Cm-3. The density of iron is 7.8 × 10″3 g Cm-3. The density of mercury is 13.6 g Cm-3.
Ans the following:
Will a piece of iron float or sink in water?
Differentiate between thrust and pressure.
Explain the following statement:
It is easier to cut with a sharp knife than with a blunt one.
A hammer exerts a force of 1.5 N on each of the two nails A and B. The area of cross section of tip of nail A is 2 mm2 while that of nail B is 6 mm2. Calculate pressure on each nail in pascal.
How is the upthrust related to the volume of the body submerged in a liquid?
Two spheres A and B, each of volume 100 cm3 is placed on water (density = 1.0 g cm−3). The sphere A is made of wood of density 0.3 g cm−3 and sphere B is made of iron of density 8.9 g cm−3.
- Find:
- The weight of each sphere, and
- The upthrust on each sphere.
- Which sphere will float? Give reason.
State whether true or false. If false, correct the statement.
The weight of fluid displaced determines the buoyant force on an object.
The point at which the force of buoyancy is supposed to act is known as ______.
