Question

what is meant by black hole
why it attracts all objects towards itself ​

Answer 1

Answer:

A black hole is a place in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying. Because no light can get out, people can't see black holes. They are invisible. Because the matter in a black hole is so dense, the force of gravity within the black hole becomes immensely strong, attracting everything within a certain radius and not even allowing light to escape.

___________________________________

Thanks to my 30 Answers please

Answer 2

Answer:

It depends on where you want to measure the velocity. Near the singularity that could be close to infinity; but at the event horizon, presuming that the in-falling object had no net relative velocity before being pulled in, its kinetic energy would be the positive equivalent of its negative potential energy. For a supermassive black hole, which has an enormous event horizon, the potential energy would be low, and so would the kinetic energy per unit of mass, so the velocity would also be low, and could probably be calculated with simple Newtonian mechanics. For stellar mass black holes the event horizon is very small, so the velocity would be much higher, and could well be high enough to require relativistic corrections.