Question

Wax cylinder of diameter 21cm and height 21cm is chipped off and shaped to form a cone of maximum volume.The chipped off wax is recast into a solid sphere.Find the diameter of the sphere

Answer 1

hello....

▶▶Vol of cylinder = 22/7 x (21/2)² x 21 =7276.5 cm³

▶▶Vol of cone = 1/3 x 22/7 x (21/2)² x 21 =2425.5 cm³

▶▶(Vol of sphere) = 7276.5 - 2425.5 = 4851 cm³

▶▶4/3 x 22/7 x r³ = 4851
                    
▶▶r³ = 4851 x 3/4 x 7/22 = 1157 5/8 cm
                    
▶▶r = ∛1157 5/8 = 10.5 cm(r) .... [d=2r]

therefore the Diameter of sphere = 10.5 x 2 = 21 cm...

thank you...