Question

In a hot water heating system, there is a cylindrical pipe of length 28 m and diameter 5 cm. Find the total radiating surface in the system.

Answer 1

Height of cylinder (h) = Length of cylindrical pipe = 28 m or 2800 cm [1 m = 100 cm] 

Diameter of circular end of pipe = 5 cm

Let ‘r’ be the radius of circular end, then 

r = diameter/2 = 5/2 cm 

We know, 

Curved surface area of cylindrical pipe = 2πrh 

= 2 x 3.14 x 5/2 x 2800

= 44000 

Therefore, the area of radiating surface is 44000 cm².