Question

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

radius is equal to 2.1 cm

1/3 π×2.1×2.1×8.4= 4/3 ×π(r)3
after cancellation
2.1×2.1×8.4=4(r)3
so , (r)3=2.1×2.1×2.1
r=2.1

Answer 2

volume of cone= 1/3×8.4×2.1×2.1
=12.348cm^3
volume of cone= volume of sphere
4÷3πr^3= 12.348
r^3= 12.348×3×7÷4×22
r^3= 47.14
r=cube root of 47.14