# Question #185b5

Jan 30, 2015

Well, the formula you've used for density is wrong. Density equals mass divided by volume, not multiplied like you show in the question.

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

I assume the three dimensions of the box (it's acutally a reactangular prism, to be precise) are expressed in mm. Indeed the volume of this box is

$V = A \cdot B \cdot C = \text{81 mm" * "57 mm" * "43 mm}$

$V = {\text{198531 mm}}^{3}$

This means that the mass of the part is

$m = \rho \cdot V = 0.0079$ $\text{g"/"mm"^3 * "198531 mm"^3 = "1568.4 g}$

If you want the answer rounded to two sig figs, the mass is

$m = \text{1600 g}$, or $m = \text{1.6 kg}$