A crown weighs 6.40 g in air and 5.90 g when completely immersed in water. If the density of water 1 g/cm^3, find the density of the crown.

12.8 cm³

Explanation:

Given;

The weight of the crown in air = 6.40 g

The weight of the crown in the water = 5.90 g

Density of water = 1 g/cm³

let the volume of crown be 'V' and the density be 'D'

Now, the weight of water displaced will be calculated as;

= Weight in air - weight in the water

or

= 6.40 - 5.90

or

The weight of water displaced = 0.50 g

now,

from the Archimedes principle, we know

the weight of the water displaced = weight of the water displaced by the volume of submerged object

thus,

0.50 = density of water * Volume of crown immersed

0.50 = 1 * V

or

V = 0.5 cm³

Now,

Density = Mass / volume

or

Density = 6.40 / 0.5 = 12.8 cm³