The radiation pressure exerted by the Sun on the Earth counteracts the gravitational attraction and puts the

Question:

The radiation pressure exerted by the Sun on the Earth counteracts the gravitational attraction and puts the Earth into an orbit that is farther from the Sun than if there were no radiation pressure. It can be shown that the distance added to Earth's orbital radius is given by (Frad/Fg)r, where Frad is the radiation force exerted on Earth by the Sun, Fg is the gravitational force between the Earth and Sun, and r is the average orbital radius.

(a) If the intensity of sunlight that strikes Earth is 1360 W/m2, what is Frad, assuming the Earth is a perfect absorber?

(b) Assuming r = 1.50 × 1011 m, what is Fg?