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प्रश्न
Why does a block of wood held under water rise to the surface when released ?
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उत्तर
A wooden block held under water floats on the surface on release because it is less dense than water. A substance floats if it is less dense than the fluid in which it is immersed after the external force is withdrawn from it.
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संबंधित प्रश्न
What is the scientific name of the 'upward force' acting on an object immersed in a liquid?
Fill in the blank with suitable word :
It is the................. force which makes objects appear lighter in water.
A body while floating sinks deeper in a liquid of low density than in a liquid of high density.
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.
Answer the following:
Will a piece of iron float or sink in mercury?
Complete the following sentence :
Pressure at all points at the same depth is ....................
Two cylindrical vessels fitted with pistons A and B of area of cross-section 8 cm2 and 320 cm2 respectively are joined at their bottom by a tube and they are completely filled with water. When a mass of 4 kg is placed on piston A, Find:
- the pressure on piston A,
- the pressure on piston B, and
- the thrust on piston B.
Select the correct option.
Thrust acting perpendicularly on the unit surface area is called
Calculate the hydrostatic pressure exerted by water at the bottom of a beaker. Take the depth of water as 40 cm, the density of water 1000 kgm−3 and g = 9.8 ms−2.
The point at which the force of buoyancy is supposed to act is known as ______.
Assertion (A): The buoyant force on a submerged rigid object can be considered to be acting at the center of mass of the object.
Reason (R): In rigid body, force distributed uniformly through its volume can be considered to be acting at the centre of mass of the body.
