Radiation: What is the net power that a person loses through radiation if her surface area is 1.20 m², if her emissivity is 0.895, if her skin temperature is 300 K, and if she is in a room that is at a temperature of 17°C? The Stefan-Boltzmann constant is 5.670 × 10^-8 W/m² · K⁴. A) 60.3 W B) 62.6 W C) 65.7 W D) 68.4 W E) 64.8 W

Question

Quizplus · Accepted Answer

The net power lost through radiation can be found using the formula:
P = σεA(T1^4 - T2^4)
where P is the power lost, σ is the Stefan-Boltzmann constant, ε is the emissivity, A is the surface area, T1 is the skin temperature and T2 is the temperature of the room.
Plugging in the given values, we get:
P = (5.670 × 10^-8 W/m^2K^4) x (0.895) x (1.20 m^2) x [(300 K)^4 - (290 K)^4]
P = 62.6 W
Therefore, the answer is B.

Radiation: What Is the Net Power That a Person Loses