Q21 of 189 Page 508

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.

Given,


Radius of hemisphere = (R) = 9 cm


Height of cone = 72 cm


Let radius of cone = r cm


We know that,


Volume of hemisphere = volume of cone


= πR3 = πr2h


= = r2 × 72


= r2 =


= r =


Radius of base of cone = 4.5 cm.


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