Question

A solid toy is in the form of a hemisphere surmounted by a right circular cone. The height of the cone is 2 cm and the diameter of the base is 4 cm. Determine the volume of the toy. If a right circular cylinder circumscribes the toy, find the difference of the volumes of the cylinder and the toy.

Answer 1

Volume of toy=volume of cone+volume of hemisphere
=>`1/3pir^2h+2/3pir^3`
given h=2cm and r=2cm
substituting values we get=>`1/3xx22/7xx4xx2+2/3xx22/7xx8`
=>`25.12(cm)^3`
if the toy is covered by a cylinder=>volume of cylinder=`pir^2h`
where r=2cm and h=4cm.
Volume of cylinder=>`22/7xx4xx4=50.26(cm)^2`
difference of volume=>`(50.26-25.12)=25.14(cm)^2`