Question

A cube-shaped block of pinewood has a surface area of 9 m and a density of 0.5 g cm-3. Its mass equals

Answer 1

Surface Area of the cube means its Total surface area.

Total surface area = 6a²

∴ 6a² = 9

∴ a² =3/2

∴ a = √1.5

∴ Volume of the Cube = 1.5√1.5 m³

Now, Using the formula,

Density  = Mass/Volume

∴ Mass = Density × Volume

∴ Mass = 0.5 × 10⁻³ × 10⁶ kg/m³ × 1.5√1.5

∴ Mass = 0.5 × 1000 × 1.5√1.5

∴ Mass = 918.5 kg.

Hope it helps.