Advertisements
Advertisements
Question
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].
Advertisements
Solution
R.D. of pure gold = 19.3
Weight of bangle in air, W1 = 25.25 gf
Weight of bangle when completely immersed in water W2 = 23.075 gf
R.D. of bangle = `W_1/(W_1 - W_2) xx "R.D. of water"`
R.D. of bangle = `25.25/(25.25 - 23.075) xx 1`
R.D. of bangle = 11.6
The bangle is not made of pure gold as its density is not 19.3.
RELATED QUESTIONS
A body of volume 100 cm3 weighs 5 kgf in air. It is completely immersed in a liquid of density 1.8 × 103 kg m-3. Find:
- The upthrust due to liquid and
- The weight of the body in liquid.
What are the units density in (i) C.G.S. and (ii) S.I. system .
'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?
A body weighs W gf in air and W1 gf when it is completely immersed in water. Find: (i) Volume of the body, (ii) Upthrust on the body and (iii) Relative density of the material of the body.
Explain the following :
Toy balloons filled with hydrogen rise to the ceiling, but if they are filled with carbon dioxide, then they sink to the floor.
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?
A wooden block floats in water with two-third of its volume submerged.
(a) Calculate the density of wood.
(b) When the same block is placed in oil, three-quarters of its volume is immersed in oil. Calculate the density of oil.
An iron nail sinks in the water while an iron ship floats on water. Explain the reason.
What can you say about the average density of a ship floating on water?
