A body heated to temperature T emits from a unit of its surface area per
unit time energy (energy flux density) proportional to the fourth degree of
temperature: φ = ϵσT4, where ϵ < 1 is the degree of blackness of the body,
σ = 5.672⋅10−8 W — is the Stefan - Boltzmann constant, T-temperature.
m2⋅K4
a. Estimate how much heat energy your body emits per unit time (the flow of
energy from the surface of your body). The degree of blackness of the body is
assumed to be 0.3
b. The sun radiates as an absolutely black body at a temperature of 6300 K.
Determine the energy flux density from the Sun’s surface.