Question

An ornament weighing 36 g in air, weighs only 34 g in water. Assuming that some copper is mixed with gold to prepare the ornament, find the amount of copper in it. The specific gravity of gold is 19.3 and that of copper is 8.9.

Answer 1

Let the amount of copper in the ornament be x g, then the volume of the ornament  will be given by the Relation,

V = Volume of copper + volume of gold

Now, Volume of the Copper = Mass/Density = x/8.9

Volume of the Gold = Mass/Density = (36 - x)/19.3

Therefore,

Volume of the Copper = (x/8.9) + (36 - x)/19.3

Now, Using the Principle of Flotation,

loss in weight = 36g - 34g

(x/8.9) + (36-x)/19.3 = 2

x ≈ 2.2 g

Hope it helps .

Answer 2

Answer:

2.2

Explanation:see pic