Advertisements
Advertisements
Question
A block of wood of mass 24 kg floats on water. The volume of wood is 0.032 m3. Find:
- the volume of block below the surface of water,
- the density of wood.
(Density of water = 1000 kg m−3)
Solution
Mass of block of wood = 24 kg
Volume of wood = 0.032 m3
(a) Upthrust = Volume of block below the surface of water (v) × density of liquid × g
Now for floatation , Upthrust = weight of the body = 24 kgf
or , 24 kgf = v × 1000 × g
or , v = `24/1000 = 0.024 "m"^3`
(b) According to the law of floatation,
`"Volume of the submerged block"/"Total volume of block" = "Density of wood"/"Density of water"`
or , `0.024/0.032 = "Density of wood"/1000`
or , Density of wood = `1000 xx 0.024/0.032 = 750 "kgm"^-3`
RELATED QUESTIONS
A body held completely immersed inside a liquid experiences two forces:
(i) F1, the force due to gravity and
(ii) F2, the buoyant force.
Draw a diagram showing the direction of these forces acting on the body and state the condition when the body will float or sink.
'The density of iron is 7800 kg m-3'. What do you understand by this statement?
Water is heated from 0°C to 10°C . How does the density of water change with temperature?
Complete the following sentence.
Density of water is .... ... kg m-3.
A piece of iron weighs 44.5 gf in air. If the density of iron is 8.9 × 103, find the weight of iron piece when immersed in water.
Explain the following :
An egg sinks in fresh water, but floats in a strong salt solution.
Explain the following :
A balloon filled with hydrogen rises to a certain height and then stops rising further.
A wooden cube of side 10 cm has mass 700 g. What part of it remains above the water surface while floating vertically on water surface?
If the density of ice is 0.9 g cm-3, then what portion of an iceberg will remain below the surface of water in sea? (Density of sea water = 1.1 g cm-3)
Select the correct option:
With the increase in the density of the fluid, the upthrust experienced by a body immersed in it:
