Which has the greater effect on the surface area of a right circular cylinder - doubling the radius or doubling the height? How would I explain this

Answer 1

The lateral area is just

2πrh, so doubling either has the same effect

The area of the ends, however, is 2πr^2, so it's likely that doubling r has a greater effect.

However, since the area is not directly proportional to either, the relative sizes of r and h will affect the outcome.