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प्रश्न
A piece of wood if left under water comes to the surface. Explain the reason.
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उत्तर
A piece of wood if left under water comes to the surface of water because the upthrust on body due to its submerged part is equal to its own weight.
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संबंधित प्रश्न
Which of the following will sink or float on water? (Density of water = 1 g Cm-3)
(a) body A having density of 500 kg m-3
The diagram given below show a body floating in three different liquids. A, B and C at different levels.
(a) In which liquid does the body experience the greatest buoyant force?
(b) Which liquid has the least density?
(c) Which liquid has the highest density?
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.
A vessel contains water up to a height of 1.5 m. Taking the density of water 103 kg m-3, acceleration due to gravity 9.8 m s-2 and area of base of vessel 100 cm2, calculate: (a) the pressure and (b) the thrust at the base of vessel.
The pressure of water on the ground floor is 40,000 Pa and on the first floor is 10,000 Pa. Find the height of the first floor. (Take : density of water = 1000 kg m-3, g = 10 m s-2)
A homogeneous block floats on water (a) partly immersed (b) completely immersed. In each case state the position of centre of buoyancy B with respect to the centre of gravity G of the block.
A balloon filled with helium gas floats in a big closed jar which is connected to an evacuating pump. What will be your observation, if air from the jar is pumped out? Explain your answer.
Most buoyant objects are those with relatively ______.
- high volume
- higher mass
- low density
- less viscosity
In a fluid, buoyant force exists because the pressure at the ______ of an object is greater than the pressure at the top.
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.
