Question

How many balls each of diameter 2 cm can be made by melting a bigger ball of diameter 6 cm?

Answer 1

Given:

Big ball diameter = 6 cm → radius R = 3 cm.

Small ball diameter = 2 cm → radius r = 1 cm.

Use the volume formula for a sphere: V = `(4/3)πr^3.`

Volume of the big ball = `(4/3)π(3)^3`

= `(4/3)π xx 27`

= 36 π cm³.

Volume of one small ball

= `(4/3)π(1)^3`

= `4/3` π cm³.

Number of small balls = (Volume of big ball) ÷ (Volume of one small ball)

= `36π ÷ (4/3 π)`

= `36 × (3/4)`

= 27