Question

is
- 9. A right circular cylinder and a sphere have the same volume and same radius. The ratio
of the areas of their curved surfaces is
If the radius of a sphere is doubled, then the percentage increase in the surface area
CL
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Answer 1

Step-by-step explanation:

Volume of sphere = (4/3)(pi)*r^3.

Volume of cylinder= (pi)*r^2*h.

The volumes of both solids being equal

(4/3)(pi)*r^3 = (pi)*r^2*h, or

(4/3)*r = h.

Surface area of sphere = 4(pi)r^2 = (pi)[4r^2] …(1)

Curved surface area of cylinder= 2(pi)rh

= (pi)2r(4/3)r …(2)

Ratio of curved surface of cylinder to the surface area of the sphere = (pi)2r(4/3)r / (pi)[4r^2] = (8/3)/4 = 2/3.