I know that black hole can feed off the material in the accretion disk and gain mass, the accretion disk is also powered by the black hole to move at a fraction of speed of light. I am wondering are the particles in the accretion disk in free fall around the black hole since they didn't get flung away?
1 Answer
They are in free fall in between collisions between one another. Due to these collisions some particles can be thrown out to escape the potential, others can fall into the hole. These collisions also cause kinetic energy loss by radiation, which is another mechanism by which matter can fall into the BH.