Energy



Intensity of sunlight at Earth's orbit  =  1360 Watts/meter^2
Earth radius                            =  6371 km

How much power does the Earth receive from the sun?
Using E=mc^2, how many kilograms of light fall on the Earth each second?

Solar wind speed                     ~  700 km/s
Solar wind density at Earth's orbit  ~  4 protons/cm^3
Mass of sun                          = 2.0*10^30 kg

What is the total power received by the Earth from the solar wind?

How much mass/second is lost from the solar wind and how much from light?



The energy required to lift 1 kg of atmosphere from the Earth into space is

Energy = G * Mass_of_Earth / Radius_of_Earth

Suppose all of the sun's energy went into removing the Earth's atmosphere. How long would it last?