Question

(Q10) A cone is 8.4cm high and the radius of its base is 2.1cm .It is melted and recast into a sphere find the radius of sphere

Answer 1

volume of cone =volume of sphere
1/3πr^2h=4/3πr^3
1/3×22/7×2.1×2.1×8.4=4/3×22/7×r^3
36.036=88/21×r^3
36.036×21/88=r^3
8 approx =r^3
r=2 approximately