Question

if the density of gold is 19.3 g/cm³, what is the mass of a gold bar (in kg) that has a volume of 21l?
hint: 1 cm³ = 1 ml
round your answer to the nearest whole number.

Explanation:

Step1: Convert volume to cm³

Since 1 L = 1000 cm³, 21 L = 21×1000 = 21000 cm³.

Step2: Use density - mass - volume formula

Density $
ho=\frac{m}{V}$, so $m =
ho\times V$. Given $
ho = 19.3$ g/cm³ and $V = 21000$ cm³, then $m=19.3\times21000 = 405300$ g.

Step3: Convert mass to kg

Since 1 kg = 1000 g, $m=\frac{405300}{1000}=405.3$ kg.

Step4: Round to nearest whole number

Rounding 405.3 kg gives 405 kg.

Answer:

405