2. a) Calculate the emissive power, E, for a surface with \(\epsilon = 0.9\), \(\rho = 0.2\), A = 0.2 m², and T = 27°C.
b) Calculate the radiosity for this same surface if it is irradiated
with G = 1000 W/m². Can radiosity ever be negative?
c) For the surface calculate the fraction of blackbody power that
falls in the wavelength range of 0 to 4 \(\mu m\) \((F_{0 \rightarrow 4 \mu m})\).
d) Does an object at 27°C emit
any thermal radiation in the
visible wavelength range? Give a
short explanation.
