Question

The volume of a sphere is 36π ft3. What is the radius of the sphere? Use the formula V =

4
3
πr3 to find your answer.

Answer 1

V=4/3(πr³) ⇒r=∛(3V/π4)=(∛3v / 4π)

r=∛(3(36π ft³) /4π)=
r=(∛108π ft³ / 4π)=(∛27 ft³) =3 ft

Answer: radius=3 ft

Answer 2

v=(4/3)pir^3
36pi=v
36pi=(4/3)pir^3
divide both sides by pi
36=(4/3)r^3
multiply both sides by 3/4 to clear fraction (4/3 times 3/4=12/12=1)
108/4=r^3
27=r^3
cube root both sides
3=r


radius=3ft