Question

A cylinder has a diameter of 20cm. The area of the curved surface is 100 cm2. [4] Find : (i) the height of the cylinder correct to one decimal place
(ii) the volume of the cylinder correct to one decimal place.

Answer 1

Answer:

given : diameter (d) = 20 CM = radius (r) = 20/2 CM = 10 CM and,

(I) C. S. A. = 100 cm^2

2πrh = 100

2 × 22/7 × 10 × h = 100

h = 100 ×1/2 ×7/22 × 1/10

h = 70/44 CM

h = 1.5 CM

(ii) volume of cylinder = πr^2h

= 22/7 × 10 × 10 × 1.5

= 3300/7 cm^2

= 471.4 cm^2