A laser produces a 6.50-mW beam of light, consisting of photons with a wavelength of 621.9 nm. (a) How many photons are emitted by the laser each second? Incorrect: Your answer is incorrect. Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. photons/s (b) The laser beam strikes a black surface and is absorbed. What is the change in the momentum of each photon that is absorbed? kg · m/s (c) What force does the laser beam exert on the black surface?