The mass of 4.5 cm3 of iron and 8 cm3 of copper is equal to 101.5g. The mass of 3 cm3 of iron is 6.8g greater than the mass of 2 cm3 of copper. Find the density of iron and the density of copper

The answer

m is the density of iron, and M is the copper's. so m=M = 101.5g

the mass of 3 cm3 of iron is 6.8g ≥ the mass of 2 cm3 of copper.

first, we know the formula

m = d x v, where m is the mass, d is the density and v is the volume;

the density of the iron is d = m / v (from the formula m = d x v). It is d = 6.8/3=2.26 g/cm3. It was assumed that m≥M=d x 2, so 6.8≥2xd, it implies

d is less than 3.4, (d≤6.8/2=3.4)

so the density of the copper is d ≤ 3.4