Advertisement Remove all ads

A Hemisphere of Lead of Radius 9 Cm is Cast into a Right Circular Cone of Height 72 Cm. Find the Radius of the Base of the Cone. - Mathematics

Sum

A hemisphere of lead of radius 9 cm is cast into a right circular cone of height 72 cm. Find the radius of the base of the cone.

Advertisement Remove all ads

Solution

Radius of hemisphere = 9 cm

Volume of hemisphere = `2/3pir^3= 2/3pixx9xx9xx9   "cm"^3`

Height of cone = 72 cm

Let the radius of the cone be r cm.

Volume of the cone `= 1/3pir^2h=1/3pir^2xx 72  "cm"^3`

The Volume of the hemisphere and cone are equal.

Therefore,

`1/3pir^2xx72xx =2/3xx9xx9xx9xx9`

`r^2 =(2xx9xx9xx9)/72 = 81/4`

`r = sqrt(81/4) = 9/2 = 4.5  "cm"` 

The radius of the base of the cone is 4.5 cm.

  Is there an error in this question or solution?
Advertisement Remove all ads

APPEARS IN

RS Aggarwal Secondary School Class 10 Maths
Chapter 19 Volume and Surface Area of Solids
Exercise 19B | Q 13 | Page 898
Advertisement Remove all ads

Video TutorialsVIEW ALL [2]

Advertisement Remove all ads
Share
Notifications

View all notifications


      Forgot password?
View in app×