A person has a thermal conductivity of 0.18 W/m·K between his inner core and his skin with an effective shell thickness of 1.6 cm between his core and skin.If his inner core is at the normal 98.6°F,and his skin has a surface area of 1.62 m²,what will be his rate of loss of thermal energy due to conduction through his skin if his skin temperature is 31.0°C?

Question

Quizplus · Accepted Answer

We can use the formula for heat transfer through conduction, which is:

Q/Δt = kA(ΔT/Δx)

where:
Q/Δt = rate of heat transfer (W)
k = thermal conductivity (W/m·K)
A = surface area (m²)
ΔT = temperature difference (K)
Δx = effective thickness (m)

We can rearrange the formula to solve for Q/Δt:

Q/Δt = kA(ΔT/Δx)

Q/Δt = 0.18 W/m·K * 1.62 m² * (98.6°F - 31.0°C) / 0.016 m

Q/Δt = 109 W

Therefore, the rate of loss of thermal energy due to conduction through his skin is 109 W, which corresponds to choice D.

A Person Has a Thermal Conductivity of 0