What is the net power that a person with surface area of 1.20 m² radiates if his emissivity is 0.895, his skin temperature is 300 K, and he is in a room that is at a temperature of 290 K? The Stefan-Boltzmann constant is 5.67 x 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 radiated by the person can be calculated using the formula:
P = εσA(Tᴾ⁴ - Tᴿᴼᴼᴹ⁴)
where 
ε = emissivity = 0.895
σ = Stefan-Boltzmann constant = 5.67 x 10⁻⁸ W/(m²•K⁴)
A = surface area = 1.20 m²
Tᴾ = skin temperature = 300 K
Tᴿᴼᴼᴹ = room temperature = 290 K

Substituting these values, we get:
P = 0.895 x 5.67 x 10⁻⁸ x 1.20 x (300⁴ - 290⁴)
P ≈ 62.6 W

Therefore, the answer is B.

What Is the Net Power That a Person with Surface