A windowpane is half a centimeter thick and has an area of 1.0 m2. The temperature difference between the inside and outside surfaces of the pane is 15° C. What is the rate of heat flow through this window? (Thermal conductivity for glass is 0.84 J/s×m×°C.)
To find the rate of heat flow through the window, we need to use the formula:
Q = k * A * ΔT / d
Where:
Q is the rate of heat flow (in watts),
k is the thermal conductivity of the material (in J/s x m x °C),
A is the area of the window (in square meters),
ΔT is the temperature difference between the inside and outside surfaces (in °C), and
d is the thickness of the window (in meters).
Given:
k = 0.84 J/s x m x °C,
A = 1.0 m^2,
ΔT = 15°C,
d = 0.5 cm = 0.005 m.
Now we can substitute the values into the formula to find the rate of heat flow:
Q = (0.84 J/s x m x °C) * (1.0 m^2) * (15°C) / (0.005 m)
After calculating the expression, we get:
Q ≈ 25,200 J/s
Therefore, the rate of heat flow through the window is approximately 25,200 Joules per second (or watts).