# An irregularly shaped object that has a mass of 40 g is placed into a graduated cylinder filled with 30 mL of water. The object causes the water to displace to 50 mL. What is the density of the object?

$\rho$ $=$ $2 \cdot g \cdot m {L}^{-} 1$.
$\rho , \text{density" ="Mass"/"Volume}$.
The object displaces a volume of $\left(50 - 30\right) \cdot m L = 20 \cdot m L$. Given that we know the mass the calculation of the density is now easy.