Black body radiation, solar spectru

Black body radiation, solar spectrum and energy from the sun
1. Use equation 17 to plot the spectral irradiance in W/m3 as a function of wavelength of a blackbody surface at 3 different temperatures. The wavelength should be in the range of 100 – 1300 nm.


2. Calculate the zenith angles needed to produce AM1.4 and AM 2.4.


3. Calculate the irradiance of sunlight for AM1.5 and for AM 2.0 at the sea level and at the top of Intanon mountain (2,565 m above the sea level). Then use the Excel to plot irradiance vs. AM for 1≤AM≤10.


4. Noting the dependence of air mass on θz. Generate a table that shows α, ψ and intensity of the sun vs. time (from 8.00 – 16.00) for a latitude of your choice on a day of your choice. Please show in detail, at least 2 values, how you come up with each answer.


5. If the temperature at the surface of the sun is about 5,700 K. Find the rate of the energy at which the sun is irradiated from each square centimeter. Assuming Stefan’s law applies to the radiation.


6. The element of an electric fire with an output of 2.5 kW is a cylinder 35 cm long and 3 cm in diameter. Calculate its temperature when in use, assuming it behaves as a black body. Neglect the ends of the cylinder.


7. A roof measures 13 m by 65 m and is blacken. If the temperature of the sun’s surface is 6000 K, and the radius of the sun is 7.5*10^8 m. The distance of the sun from the earth is 1.5*10^8 km. Calculate how much solar energy is incident on the roof per minute, assuming that one third of the intensity is lost in passing through the earth’s atmosphere. Assume the roof is normal to the sun’s rays.