Question

calculate the density of an object, if the mass is 30 g and the volume is 71 ml.
density = \frac{mass}{volume}
remember to select an answer with the correct number of significant figures.

Explanation:

Step1: Identify the formula

The formula for density is $
ho=\frac{m}{V}$, where $
ho$ is density, $m$ is mass and $V$ is volume.

Step2: Substitute values

Given $m = 39\ g$ and $V=71\ mL$. Substitute into the formula: $
ho=\frac{39\ g}{71\ mL}$.

Step3: Calculate the density

$
ho=\frac{39}{71}\ g/mL\approx0.55\ g/mL$ (rounded to two - significant figures as 39 and 71 have two significant figures).

Answer:

0.55 g/mL