In a hot water heating system, there is a cylindrical pipe of length 28 m and diameter 5 cm.
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. (Take π = 3.14)

Solution:

Given that

Height of cylinder = length of cylindrical pipe

= 28 m

Radius(r) of circular end of pipe = 5/2 = 2.5 cm = 0.025 m

Curved surface area of cylindrical pipe $=2 \pi r h=2 * 3.14 * 0.035 * 30=4.4 \mathrm{~m}^{2}$

Therefore the area of radiating surface of the system is $4.4 \mathrm{~m}^{2}$ or $44000 \mathrm{~cm}^{2}$.