Advertisements
Advertisements
Question
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?
Advertisements
Solution
Given, Side of wooden cube = 10 cm
Hence, Volume of wooden cube = 10 cm × 10 cm × 10 cm = 1000 cm3
Mass = 700 g
Density = `"mass"/"volume"`
∴ Density of wooden cube = `700/1000` = 0.7 g cm-3
By the principle of floatation,
`"Volume of immersed part"/"Total volume" = "Density of wood"/"Density of water"`
Density of water = 1 g cm-3
Density of wooden cube = 0.7 g cm-3
∴ `"Volume of immersed part"/"Total volume" = 0.7/1`
Hence, fraction submerged = 0.7
Height of wooden cube = 10 cm
Part of wooden cube which is submerged = 10 x 0.7 = 7 cm
Therefore, part above water = 10 - 7 = 3 cm
Hence, 3 cm of height of wooden cube remains above water while floating.
APPEARS IN
RELATED QUESTIONS
The density of copper is 8.83 g cm-3. Express it in kg m-3.
A jeweller claims that he makes ornaments of pure gold that has a relative density of 19.3. He sells a bangle weighing 25.25 gf to a person. The clever customer weighs the bangle when immersed in water and finds that it weighs 23.075 gf in water. With the help of suitable calculations, find out whether the ornament is made of pure gold or not.
[Hint : calculate R.D. of material of bangle which comes out to be 11.6].
How does the density ρs of a substance determine whether a solid piece of that substance will float or sink in a given liquid ρL?
A solid lighter than water is found to weigh 7.5 gf in air. When tied to a sinker the combination is found to weigh .If the sinker alone weighs 72.5 gf in water, find R.D. of solid.
An inflated balloon is placed inside a big glass jar which is connected to an evacuating pump. What will you observe when the evacuating pump starts working? Give a reason for your answer.
A solid body weighs 2.10 N. in air. Its relative density is 8.4. How much will the body weigh if placed
(1) in water,
(2) in liquid of relative density 1.2?
Select the correct option:
A body has density 9.6 gcm -3. Its density in SI system is:
A body weighs 300 gf in air and 280 gf when completely immersed in water. Calculate:
(i) The loss in weight of the body,
(ii) The upthrust on the body.
A wooden cube of side 10 cm has a mass of 700 g. It will float in the water with:
(a) Half of its volume inside the water
(b) 3 cm height above the water surface
(c) 7 cm height above the water surface
(d) Just inside the water surface.
