Question

A new penny has a mass of 2.49 grams and occupies 0.349 cm cubed. If pure copper has a density of 8.96 g/cm cubed, is the new penny put copper?

Answer 1

Answer: The new penny is not pure copper

Explanation:

Density $\rho$ is defined as a relation between the mass $m$ and the volume $V$:

$\rho=\frac{m}{V}$

Now, we are told the density of pure copper is:

$\rho_{copper}=8.96 g/cm^{3}$

And we are given the mass and volume of the new penny, with which we can calculate its density:

$\rho_{penny}=\frac{m_{penny}}{V_{penny}}=\frac{2.49 g}{0.349 cm^{3}}$

$\rho_{penny}=7.13 g/cm^{3}$ As we can see the density of this penny is not equal to the density of pure copper, hence the new penny is not pure copper.