Mensuration-58

From Homeworkwiki

Jump to: navigation, search

A right circular cone is 3.6 cm high and the radius of its base is 1.6 cm. It is melted
and recast into a right circular cone with radius of its base as 1.2 cm. Find the height.

Solution: For cone, h = 3.6 cm, r = 1.6 cm

Volume of the given cone = 1/3 Π r2 h = (1/3 x 22/7 x 1.6 x 1.6 x 3.6) cm3

Radius of the second cone = 1.2 cm. Let its height be h1, then

Volume of the second cone = 1/3 Π r2 h = 1/3 x 22/7 x 1.2 x 1.2 x h1

Since the volume of the cones would be equal, so

1/3 x 22/7 x 1.2 x 1.2 x h1 = 1/3 x 22/7 x 1.6 x 1.6 x 3.6

=> h1 = (1.6 x 1.6 x 3.6) / (1.2 x 1.2) = 6.4

Hence, the height of the second cone is 6.4 cm

Personal tools
McAfee SECURE sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams