Aballoon filled with helium at 20°c, 1 bar and a volume of 0.5 m3 is moving with a velocity of 15 m/s at an elevation of 0.5 km relative to an exergy reference environment for which to-20°c, po 1 bar. using the ideal gas model. determine the specific exergy of the helium, in kj

Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 k. calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. what is the wavelength ? , below which 10% of the emission is concentrated? what is the wavelength ? 2 above which 10% of the emission is concentrated? determine the wavelength at which maximum spectral emissive power occurs. what is the irradiation incident on a small object placed inside the enclosure?