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प्रश्न
Write an expression for the pressure at a point inside a liquid. Explain the meaning of the symbols used.
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उत्तर
P = Po + h ρ g
Here, P = Pressure exerted at a point in the liquid
Po = Atmospheric pressure
h = Depth of the point below the free surface
`ρ` = Density of the liquid
g = Acceleration due to gravity
संबंधित प्रश्न
What causes buoyant force (or upthrust) on a boat ?
A body floats in a liquid when its weight becomes equal to the weight of the liquid displaced by its submerged part.
Describe a simple experiment to demonstrate that a liquid enclosed in a vessel exerts pressure in all directions.
State three factors on which the pressure at a point in a liquid depends.
The diagram below in Fig. 4.12 shows a device which makes the use of the principle of transmission of pressure.
- Name the parts labelled by the letters X and Y.
- Describe what happens to valves A and B and to the quantity of water in the two cylinders when the lever arm is moved down.
- Give reasons for what happens to valves A and B in part (ii).
- What happens when the release valve is opened?
- What happens to valve B in cylinder P when the lever arm is moved up?
- Give a reason for your answer in part (v).
- State one use of the above device.
The pressure inside a liquid of density p at a depth h is :
Describe an experiment to show that a body immersed in a liquid appears lighter than it really is.
The mass of a block made of certain material is 13.5 kg and its volume is 15 × 10-3 m3.
(a) Calculate upthrust on the block if it is held fully immersed in water.
(b) Will the block float or sink in water when released? Give a reason for your answer.
(c) What will be the upthrust on block while floating?
Take density of water = 1000 kg m-3.
Select the correct option:
When an object sinks in a liquid, its:
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.
