How to find internal radius of a hemispheral

Question

A spoon used to measuring in cookery consists of a hemispheral bowl and a handle. The internal volume of the hemispheral bowl is 20cm3. The handle of the length is 5cm

Answer 1

The formula for the volume of a sphere is V = 4·pi·r³/3 where r = the sphere's radius.  You want a hemisphere, which is half of a sphere.  Hence:

 

     V = 2·pi·r³/3

     20 = 2·pi·r³/3

 

Solve for r.