Question

(a) Write down an equation that defines density.
(b) $5kg$ of material A occupy $20m^3$ whereas $20kg$ of material B occupy $90c{m}^3$. Which has the greater density : A or B? Support your answer with calculations.

Answer 1

(a) Density of substance = $\frac{massofsubstance}{volumeofsubstance}$
(b) For material A:
Mass = 5 kg
Volume = $20c{m}^3=20\times {10}^{-6}{m}^3$
Density of material A = $\frac{5}{20\times {10}^{-6}}=0.25\times {10}^{6}kg/m^3$
For material B:
Mass = 20 kg
Volume = $90c{m}^3=90\times {10}^{-6}{m}^3$
Density of material A = $\frac{20}{90\times {10}^{-6}}=0.22\times {10}^{6}kg/m^3$
Density of material A is more than density of material B.