Question

Heat is lost steadily through a 0.5 cm thick 2 m x 3 m glass window whose thermal conductivity is 0.7 W/(m*K). The inner and outer surface temperatures of the glass are measured to be 12 degree C to 9 degree C. The rate of heat loss by conduction through the glass is:

A. 2520 W
B. 5040 W
C. 17600 W
D. 420 W
E. 1256 W

Answer 1

The rate of heat loss by conduction through a 0.5 cm thick, 2 m x 3 m glass window with a thermal conductivity of 0.7 W/(m*K), and an internal and external temperature difference of 3°C, is calculated using the formula for thermal conduction, resulting in a loss of 2520 W.

Step-by-step explanation:

The heat transfer concept is known as thermal conduction. To calculate the rate of heat loss by conduction through the glass, we use the formula ΔQ/Δt = kA(ΔT/Δx), where ΔQ/Δt is the rate of heat transfer (in Watts), k is the thermal conductivity, A is the area through which heat is transferred, ΔT is the temperature difference, and Δx is the thickness of the material. For a glass window with a thermal conductivity of 0.7 W/(m*K), with a thickness of 0.005 m (0.5 cm), an area of 6 m² (2 m x 3 m), and a temperature difference of 3°C (12°C - 9°C), the rate of heat loss is calculated as follows:

ΔQ/Δt = (0.7 W/(m*K)) * (6 m²) * ((12°C - 9°C) / 0.005 m) = 2520 W. Therefore, the correct answer is A. 2520 W.