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प्रश्न
Explain the following statement:
It is easier to cut with a sharp knife than with a blunt one.
उत्तर
It is easier to cut with a sharp knife because even a small thrust causes great pressure at the edges and cutting can be done with less effort.
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संबंधित प्रश्न
How does the density of a body and that of a liquid determine whether the body will float or sink into that liquid?
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 wood is floating on water with its dimensions 50 cm x 50 cm x 50 cm inside water. Calculate the buoyant force acting on the block. Take g = 9.8 N kg-1.
A body of mass 3.5 kg displaces 1000 cm3 of water when fully immersed inside it. Calculate:
- the volume of body,
- the upthrust on body and
- the apparent weight of body in water.
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.
Figure shows the same block of wood floating in three different liquids A, B and C of densities ρ1, ρ2 and ρ3 respectively. Which of the liquid has the highest density? Give a reason for your answer.
A beaker contains a liquid of density ‘ρ’ up to height ‘h’ such that ‘PA’ is atmospheric pressure and ‘g’ is the acceleration due to gravity. Answer the following questions:
- What is the pressure on the free surface of the liquid?
- What is the pressure on the base of the beaker?
- What is the lateral pressure at the base on the inner walls of the beaker?
The blood pressure reading of a patient is recorded 160/100. Express the lower pressure in SI units.
[Take density of mercury as 13.6 × 103 kgm−3 and the value of ‘g’ as 10 ms−2]
Select the correct option:
When an object sinks in a liquid, its:
What is meant by up thrust?
