Can light apply force? (F=ma) Please explain.
The best way to describe force of light on a particle is absorption and then emission of the light. When the light is absorbed, so are the light's energy and momentum. When the light is emitted, so are the energy and momentum. If the light is emitted in a direction different from the original direction, there is a change of momentum in the particle. This momentum change is seen as a change of the particle's motion.