Assume the intensity of sunlight is 1.00 kW/m2 at a particular location. A highly reflecting concave mirror is to be pointed toward the Sun to produce a power of at least 350 W at the image.
(a) Find the required radius Ra of the circular face area of the mirror.
(b) Now suppose the light intensity is to be at least 120 kW/m2 at the image find the required relationship between Ra and the radius of curvature R of the mirror. The disk of the Sun subtends an angle of 0.533° at the Earth.