Question.
In a hot water heating system, there is a cylindrical pipe of length $28 \mathrm{~m}$ and diameter $5 \mathrm{~cm}$. Find the total radiating surface in the system. $\left[\right.$ Assume $\left.\pi=\frac{22}{7}\right]$
Solution:
Height (h) of cylindrical pipe = Length of cylindrical pipe = 28 m
Radius (r) of circular end of pipe = = 2.5 cm = 0.025 m
CSA of cylindrical pipe $=2 \pi r h$
$=\left(2 \times \frac{22}{7} \times 0.025 \times 28\right) \mathrm{m}^{2}$
$=4.4 \mathrm{~m}^{2}$
The area of the radiating surface of the system is $4.4 \mathrm{~m}^{2}$.
Height (h) of cylindrical pipe = Length of cylindrical pipe = 28 m
Radius (r) of circular end of pipe = = 2.5 cm = 0.025 m
CSA of cylindrical pipe $=2 \pi r h$
$=\left(2 \times \frac{22}{7} \times 0.025 \times 28\right) \mathrm{m}^{2}$
$=4.4 \mathrm{~m}^{2}$
The area of the radiating surface of the system is $4.4 \mathrm{~m}^{2}$.