Basic question, I know... but.. When a star collapses and becomes a black hole, is it the same mass and does it have the same gravitational force of the original star? I heard something about it throwing off some of that mass in the process. And perhaps some aspect at the quantum level affects the gravity or mass. As an extension of the question, once a BH consumes other masses, does the net mass equal the sum of the individual masses and is the gravitational force the sum of the gravitational forces of the original objects?