Find the number of metallic circular discs with 1.5 cm base diameter and height 0.2 cm to be melted to form a circular cylinder of height 10 cm and diameter 4.5 cm.

Solution:

Given height of the circular cylinder, h = 10 cm

Diameter of circular cylinder = 4.5 cm

So radius, r = 4.5/2 = 2.25 cm

Volume of circular cylinder = r²h

= ×2.25²×10 = 50.625 cm³

Base diameter of circular disc = 1.5 cm

So radius, r = 1.5/2 = 0.75 cm

Height of the circular disc, h = 0.2 cm

Volume of circular disc = r²h

= ×0.75² ×0.2

= 0.1125 cm³

Number of circular discs made from cylinder = 50.625/0.1125 = 450

Hence the number of circular discs made from cylinder is 450.