Question

Katie approximated the volume and the surface area for a ball she was using for some exercises by assuming the ball is a sphere. She was surprised when the numerical value of the volume in cubic inches was the same as the numerical value of the surface area in square inches. What is the radius of the ball?

Answer 1

Answer:

3

Step-by-step explanation:

Volume of sphere:

4/3 * pi * r^3

Surface Area of Sphere:

4 * pi * r^2

So if V = SA

4/3 * pi * r^3 = 4 * pi * r^2

4/3 * pi * r^3 = 4 * pi * r^2

1/3 * r^3 = r^2

1/3 * r = 1

r = 3