Chapter 25, Problem 100GP

Orbital Drift The radiation pressure exerted by the Sun on the Earth counteracts the gravitational attraction and pub 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 (F_rad/F₉)r, where F_rad is the radiation force exerted on Earth by the Sun. F₉ 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 F_rad, assuming the Earth is a perfect absorber? (b) Assuming r= 1 50 x 10¹¹ m what is F₀? (c) What is the additional distance added to Earth’s orbital radius by the radiation pressure?