Question

A large steam pipe is covered with 1.3-cm-thick insulating material of thermal conductivity 0.25 J/(s m °C). How much energy is lost every second when the steam is at 195 °C and the outside of the pipe has a temperature of 20°C? The pipe has a circumference of 7.5 m and a length of 70 m. Neglect losses through the ends of the pipe.

Answer 1

Here,

The thickness is,

L= 1.3 cm= 1.3*10^-2 m

Then,