How to solve this problem using Archimedes' principle?

[powersys]

using archamides principle to solve

A 1967 Kennedy half-dollar has a mass of 1.150 x 10^(-2) kg (0.0115 kg). The coin is a mixture of silver and copper, and in water the coin weighs 0.1011 N. Determine the mass of silver in the coin. (Given ρ(gold) = 19.3 x 10^3 kgm^3; ρ(silver) = 10.5 x 10^3 kgm^3)

Thanks in advance.

 

[flatulent]

using archimedes principle to solve

You should not ask others to do your homework for you. But a hint. From the given data you can determine the volume of the coin. From the coin volume and the density of the two metals you can find their ratios and then their absolute amounts.

 

[powersys]

how to solve archimedes principle

Hi flatulent, it's not homework as I'm not a student. Someone asked me this question and I could not answer him and that's why I wish to have advices here. He told me that the solution he got was not the same to the answer given in the reference book. The answer given in the reference book is 6.34 x 10^(-3) kg. He wishes to confirm whether his method is correct or not. Thanks.

 

[flatulent]

how to solve archimedes

Sorry about that. Here is a more detailed method.

1. From the difference in coin weight in and out of water you can get the weight of water displaced.

2. From the density of water you can get the volume of the coin.

3. From the coin volume and weight you can get the coin density.

4. Then find the ratio of constituent densities to equal the coin density.