Advertisements
Advertisements
Question
A piece of wood of uniform cross section and height 15 cm floats vertically with its height 10 cm in water and 12 cm in spirit. Find the densities of wood and spirit.
Advertisements
Solution
Let densities of water, wood and spirit are ρ, ρw and ρs respectively.
Let A be the area of the wooden block.
Total volume of the wooden block is, V = 15A
1. Mass of wood = Mass of water displaced by the wood
Vρwg = A×10×ρ×g
ρw = `(A xx 10 xx ρ xx "g")/(15 xx A xx "g") = 0.67` g/cm3
2. Mass of the wood = Mass of then spirit displaced
Vρwg = A×12×ρs×g
ρs = 0.83 g/cm3
APPEARS IN
RELATED QUESTIONS
Assuming the density of air to be 1.295 kg m-3, find the fall in barometric height in mm of Hg at a height of 107 m above the sea level. Take density of mercury = 13.6 × 103 kg m-3.
'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 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.
A hollow cylinder of copper of length 25 cm and area of cross-section 15 cm2, floats in water with 3/5 of its length inside water. Calculate:
(1) apparent density of a hollow copper cylinder.
(2) wt. of cylinder.
(3) extra force required to completely submerge it in water.
A cork cut in the form of a cylinder floats in alcohol of density 0.8 gcm-3, such that 3/4 of its length is outside alcohol. If the total length of the cylinder is 35 cm and area of cross-section 25 cm2, calculate:
(1) density of cork
(2) wt. of cork
(3) extra force required to submerge it in alcohol
Select the correct option:
A body has density 9.6 gcm -3. Its density in SI system is:
Write the SI units of Weight of a body
