The diameter of a metallic ball is 4.2 cm. What is the mass of the ball, if the density of the metal is 8.9 g per cm³? (Assume π = 22/7)

Given: Diameter = 4.2 cm

Radius, r = 4.2/2 cm = 2.1 cm

We know that volume of the sphere = 4/3 πr³

V = (4/3) × (22/7) × (2.1)³

The volume of the metallic ball = 38.808 cm³

We know that, Density = Mass/Volume

Mass = Density × volume

= (8.9 × 38.808) g

= 345.3912 g

Thus, the mass of the ball is 345.39 g (approx).