In: Physics
A laser emits a cylindrical beam of light 4.0 mm in diameter. The average power of the laser is 2.8 mW . The laser shines its light on a perfectly absorbing surface.
How much energy does the surface receive in 14 s ?
What is the radiation pressure exerted by the beam?
If the light beam falls in a perfectly reflecting surface the radiation pressure will be twice of the pressure on a perfectly absorbing surface as the change in momentum is double for reflecting surface than the absorbing surface.