Question

A jeweler claims that he makes ornament of pure gold of relative density $19.3$. 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 $11.6$].

Answer 1

loss of weight in water = 25.250 - 23.075

= 2.175gf

loss of weight in water = mass of displaced water

= (volume of displaced water) $\times$ (density of water)

= 2.175gf

if we consider density of water

= 1 $\frac{g}{cc}$, then,

volume of displaced water = volume of bangle = 2.175 $c{m}^3$

mass of bangle,

if it is made by pure gold of relative density 19.3 = 2.175 $\times$19.3

= 42 gf

Conclusion :-

Bangle is not made by pure gold of relative density 19.3