A solid sphere of diameter 18 cm is melted and cast into a right circular cone whose base radius is 1/√2 times its slant height. If the radius of the sphere and the cone can are equal, then how many such cones can be made out of the sphere? 

A solid sphere of diameter 18 cm is melted and cast into a right circular cone whose base radius is 1/√2 times its slant height. If the radius of the sphere and the cone can are equal, then how many such cones can be made out of the sphere?  Correct Answer 4

Calculation:

The volume of sphere and all cones will be equal,

Let radius of sphere and cone be r cm.

V sphere = 4/3 π r3     

V cone = 1/3 π r2 h

A.T.Q

r = 1/√2 l, Multiplying by 2 and squaring both sides,

⇒ 4r2 = 2l2

⇒ 4r2 = 2(h2 + r2)

⇒ 2r2 = 2h2

⇒ r = h

∴ V cone = 1/3 π r3

1/3 π r3 = 4/3 π r3

∴ 4 cones can be made out of the sphere.

Related Questions

If the given solid metallic right circular cone is melted and recast into a right circular cylinder having the same radius, what would be the height of this cylinder? I. The sum and product of the radius and height of the cone are 31 cm and 147 cm2 respectively. II. Total surface area of the cone is 550 cm2.