Question
obiem 4 A wall is composed of two materials. Material 1 has a thickness of 3.36 em and a therma conductivity of 0.1 while material 2 has a thickness of 8.8 cm and a conductivity of 1. If the temperature difference inside to outside is 25 C and the wall has an area of 10 m2, what is the energy loss per second to the nearest watt? 1 2 In Problem 4 if the inside temperature is 20.7 what is the temperature of the interface to the nearest degree Celsius? Problem In the figure (not to scale) a special wall has three metal studs with conductivity of 453 W/m K The wall otherwise has a conductivity of 1.01 W/m K. What is the energy loss per second to the nearest watt if the temperature difference across the wall is 25 C? 0.I m 0.2 ml 10 m 0.2 mI 0.2 ml Top View of a 3 m high wall
Explanation / Answer
delta_Q/delta_T = kA delta_T/x
where x is thickness of material
= A* delta_T( k1/x1+k2/x2)
= 10* 25 *( 0.1/3.36 + 1/8.8) *100
= 3584.95 Watt
Given inside temp = 20.7
Interface temp = 20.7 + 2 5= 45.7 degree
