Question

Using Vernier Callipers, the diameter of a brass metal bob the bob is determined as 1.96 cm and the mass is 29.95 g. Find the density to correct significant figures .

Answer 1

Density = Mass / Volume.

Mass = 29.95 g.

Volume,  diameter = 1.96 cm , radius = 1.96/2 = 0.98 cm.

The metal bob is a sphere

Volume of sphere = (4/3)πr³= (4/3)*π*0.96³ ≈ 3.9425 cm³

Density = 29.95g / 3.9425 cm³ ≈ 7.597 g/cm³

Recall 1 g/cm³ = 1000 kg/m³

Density ≈ 7.597 g/cm³ or 759.7 kg/m³