Question

How many solid cylinders of radius 6 cm and height 12 cm can be made by melting a solid sphere of radius 18 cm? 

Activity: Radius of the sphere, r = 18 cm

For cylinder, radius R = 6 cm, height H = 12 cm 

∴ Number of cylinders can be made =`"Volume of the sphere"/square`

`= (4/3 pir^3)/square`

`= (4/3 xx 18 xx 18 xx 18)/square`

= `square`

Answer 1

∴ Number of cylinders can be made =`"Volume of the sphere"/"Volume of cylinder"`

`= (4/3 pi"r"^3)/(pi "r"^2"h")`

`= (4/3 xx 18 xx 18 xx 18)/(6 xx 6 xx 12)`

`= (4 xx 18 xx 18 xx 18)/(3 xx 6 xx 6 xx 12)`

= 18