A person's body is covered with 1.4 m2 of wool clothing. The thickness of the wool is 1.3 10-3 m. The temperature at the outside surface of the wool is 14°C, and the skin temperature is 36°C. How much heat per second does the person lose due to conduction?
You have a nice formula for this:
Heat transfer rate= K *area*deltaTemp/thickness You need to look up K, the heat conduction coefficent (joules/(C-m) ).
565.3W
To find the heat lost per second due to conduction, we can use the formula:
Heat transfer rate = K * area * ΔTemp / thickness
However, we first need to find the value of K, which is the heat conduction coefficient. The heat conduction coefficient represents the material's ability to conduct heat. It is measured in joules per second per degree Celsius per meter (J/(s·°C·m)).
Different materials have different values for the heat conduction coefficient. In this case, since the material is wool, we need to find the specific value for wool's heat conduction coefficient.
Once we have the value for K, we can use the given values to calculate the rate of heat transfer.
To find K for wool, we can consult reference tables or reliable sources such as engineering handbooks, material property databases, or research papers. Let's assume the value of K for wool to be K = 0.04 J/(s·°C·m).
Now we can substitute the given values into the formula and solve for the heat transfer rate:
Area = 1.4 m² (given)
ΔTemp = (Skin Temperature) - (Outside Surface Temperature) = 36°C - 14°C = 22°C
Thickness = 1.3 * 10^(-3) m (given)
K = 0.04 J/(s·°C·m) (approximated)
Heat transfer rate = 0.04 * 1.4 * 22 / (1.3 * 10^(-3))
Simplifying the expression:
Heat transfer rate = 0.04 * 1.4 * 22 / 0.0013
Heat transfer rate = 1.232 / 0.0013
Heat transfer rate ≈ 948.31 J/s
Therefore, the person loses approximately 948.31 Joules of heat per second due to conduction.