The energy of sunlight hitting the earth is about 1400 W/m^2 (where 1 W= 1 J/s) in mid day.
a). How much work is equivalent to the energy of light shining on 1m^2 area of the earth in 1 s?
b). If you assume that all the photons hitting the earth have a wavelength of 500 nm, estimate the number of photons striking a 1 m^2 area of the earth in 1 s.
c). Given that the sun is about 150 million km from the earth, estimate the total output of the sun (in W).