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प्रश्न
Higher Order Thinking Skill.
How does a fish manage to rise up and move down in water?
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उत्तर
Fish has an internal swim bladder which is filled with gas. When it needs to rise or descend, it changes the volume and its density by filling this bladder with oxygen collected from the surrounding water through gills. When the bladder is filled with oxygen gas, the fish has a greater volume, with minimal increase in weight. When the bladder is expanded, it displaces more water and so experiences a greater force of buoyancy.
When the bladder is completely inflated, the fish has maximum volume and is pushed to the surface. When the bladder is completely deflated, the fish has minimum volume and sinks to the ocean floor.
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संबंधित प्रश्न
A body X sinks in water, but a body Y floats on water. The density of the body X is ......... than the density of body Y.
When does an object float or sink when placed on the surface of a liquid ?
Name the S.I. unit of density. How is it related to g Cm-3?
Complete the following sentence :
Pressure is .................... in all directions about a point in a liquid.
A block of iron of mass 7.5 kg and of dimensions 12 cm × 8 cm × 10 cm is kept on a table top on its base of side 12 cm × 8 cm.
Calculate:
- Thrust and
- Pressure exerted on the table top
Take 1 kgf = 10 N.
The area of base of a cylindrical vessel is 300 cm2. Water (density= 1000 kg m-3) is poured into it up to a depth of 6 cm. Calculate : (a) the pressure and (b) the thrust of water on the base. (g = 10m s-2.
Describe an experiment to show that a body immersed in a liquid appears lighter than it really is.
Complete the following sentence.
Mass = .................... × density
What is the centre of buoyancy? State its position for a floating body with respect to the centre of gravity of the body.
Select the correct option:
When a body is wholly or partially immersed in a liquid, it experiences a buoyant force which is equal to:
