# Given 5*cm^3 blocks of silver and gold, what are the masses of each metal sample, given the following densities...?

## ${\rho}_{\text{Ag}} = 10.5 \cdot g \cdot c {m}^{-} 3$ ${\rho}_{\text{Au}} = 19.3 \cdot g \cdot c {m}^{-} 3$.

Sep 3, 2016

Clearly, the gold would have twice the mass of the silver.

#### Explanation:

$\text{Density, } \rho$ $=$ $\text{Mass"/"Volume}$

Now you have metals with the same volume. And thus the mass of the gold cube would be approx. twice that of the silver cube (and a lot more expensive as well!).

We can work out the mass of each lump by using the equation above:

$\text{Mass"=rhoxx"volume}$.

${\text{Mass}}_{A g} = 10.5 \cdot g \cdot c {m}^{-} 3 \times 5 \cdot c {m}^{3}$ $\cong 53 \cdot g \text{ silver metal}$.

${\text{Mass}}_{A u} = 19.3 \cdot g \cdot c {m}^{-} 3 \times 5 \cdot c {m}^{3}$ $\cong 100 \cdot g \text{ gold metal}$.

If you have a national paper handy, it will always list the price of precious metals (gold, rhodium, platinum) in the stocks and shares section. It is interesting to learn the market price. Of course, speculators trade in precious metals trying to make a killing. Also of course, they probably use some absurd unit as $\text{troy ounce}$ in preference to grams, the creatures.