Discuss the below:
Light intensity: Momentum of photons, mirrors, and velocity
Q: The intensity of light with a mean wavelength of 854 nm falling on a solar sail is 140 watts/m^2. The sail is oriented perpendicular to the direction of the incoming light, in order to intercept as much light as possible.
- What is the total momentum of the photons falling on 52000 m^2 of the sail every second?
- If the sail is a perfect mirror, reflecting the photons without any absorption or change in their momentum, then what average force is exerted on the sail?
- How long would it take to accelerate a 1440 kg craft (mass includes that of the sail) from rest to velocity .1 c using such a sail?