If the radius of a cylinder is doubled, what will be the ratio between the volume of the new cylinder to the volume of the original one?

Answer 1

Because volumes are CUBED, and radius is "plain old" units (linear), then the ratio of the radii will be

r_big : r_small = 2 : 1 or 2/1

Since Volume is CUBED, we need to CUBE the radii ratio to get the volume ratio. 2³/1³ = 8/1 or 8:1

Volumes are in 8 to 1 ratio. Or 8/1