Physics 408 --Exam 2 Name__________________________________________ You are graded on your work, with partial credit where it is deserved. Summary: Physics 408 -- Exam 2 Name__________________________________________ You are graded on your work, with partial credit where it is deserved. Please give clear, well-organized solutions. h = 6.63 x i0 J s [Planck's constant] k = 1.38 X 1023 J/K [Boltzmann constant] = 5.67 X 10--8 m2K4 [Stefan-Boltzmann constant] c = 3.OOx 108 rn/s [speed of light] E --jii/kT e / ±1 1. The distance between the Earth and the Sun is R = 1.50 X 1011 m, and the radius of the Sun is r = 6.96 x 108 m . The radiant energy flux (or intensity) of sunlight at the position of the Earth is S = solar constant = 1.36 x i03 ---. (a) (9) Calculate the total rate of energy generation of the Sun in J/s (b) (9) Recalling the Stefan-Boltzmann law, energy flux from perfect blackbody = B T4, calculate the temperature at the surface of the Sun. (c) (9) The solar spectrum peaks at about 518 nm, or 518 x io9 m. According to the Wien displacement law, with the Planck distribution written in terms of the wavelength A, A hc peak Collections: Physics