The radius of the internal and external surface of a hollow spherical shell are 3cm and 5cm respectively. If it is melted and recast into a solid cylinder of height `2 2/3c mdot` Find the diameter of the cylinder.

Explanation

Base radius of a solid cylinder,` r=7cm`
Let the height of the cylinder` =h`
As per given statement
The hollow spherical shell is melted into a solid cylinder, so
the volume of solid cylinder = volume of a spherical shell
`pir^2h=4/3pi(r2^3-r1^3)`( r1 and r2be the intenal and external base radi of spherical shell.)
`49h=4/3(125-127)`
`h=8/3cm`