Consider a perfectly reflecting mirror oriented so that solar radiation of intensity I is incident upon, and perpendicular to, the reflective surface of the mirror. If the mirror has surface area A, what is Frad, the magnitude of the average force due to the radiation pressure of the sunlight on the mirror? Express your answer in terms of the intensity I, the mirror's surface area A, and the speed of light c.
Frad =
To solve the second part of this problem you will need to know the following:
the mass of the sun, Msun=2.0×1030kg, the intensity of sunlight as a function of the distance, R, from the sun,
Isun(R)=3.2×1025WR2,
and
the gravitational constant G=6.67×10−11m3/(kg⋅s2).
Suppose that the mirror described in Part A is initially at rest a distance R away from the sun. What is the critical value of area density for the mirror at which the radiation pressure exactly cancels out the gravitational attraction from the sun?
Express your answer numerically, to two significant figures, in units of kilograms per meter squared.