A laser produces a 3.10-mW beam of light, consisting of photons with a wavelength of 610.1 nm. (a) How many photons are emitted by the laser each second? 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? N