Question

A circular metal sheet 48 cm in diameter and 2 mm thick is melted and recast into a cylindrical bar 6 cm in diameter. How long is the bar?​

Answer 1

12.8cm

Explanation:

radius = 0.5 X diameter

2mm = 0.2cm

volume of circular metal sheet = π r² h = π (24)² (0.2) = 115.2π cm³.

volume, V, of cylindrical bar = π r² L

L = V/(π r²)

= 115.2π / (π (3)²)

= 115.2/ 9

= 12.8cm