Question

b. The mass of 15 cm3 of aluminium is 180 g. Find
i.) the density of aluminium in kg/m3
ii) relative density of aluminium.​

Answer 1

Given: Mass of 15 cm³ of aluminium = 180 g

To Find: Density of Aluminium in kg/m³ and it's relative density.

(A) Density:-

We know,

Density = (Mass)/(Volume)

→ Density of Al = (180 g)/(15 cm³)

= (0.18 kg)/(15 ÷ 1000000 m³)

[Since, 1 kg = 1000 g and 1 m³ = 1000000 cm³]

= [(0.18 kg) × (1000000)]/(15 m³)

= (180000 kg)/(15 m³)

= 12000 kg/m³

∴ The density of Aluminium in kg/m³ is 12000 kg/m³.

(B) Relative Density:-

We know,

Relative density = (Density of an object)/(Density of water)

also,

density of water = 1000 kg/m³

∴ Relative density = (12000 kg/m³)/(1000 kg/m³)

→ Relative density = 12 : 1

∴ Relative density of Aluminium is 12 : 1.