Problem
A satellite in Earth orbit maintains a panel of solar cells of area 2.60 m2 oriented perpendicular to the direction of the Sun’s rays. Solar energy arrives at the rate of 1.39 kW/m2 (energy/area/time)
(a) at what rate does Solar energy strike the panel?
rate=energy/time = 1.39(2.60) =3.61 kW
(b) at what rate are Solar photons absorbed ? (?=550nm)
each photon carries E=hc/? =(6.63x10-34)(3x108)/(550x10-9)=3.61x10-19 J
photons/time = (3.61x103)/(3.61x10-19 ) = 1022 /sec