Bye for now. First we begin with a star ten times the mass of the sun, and we focuse on the stars positive and negative forces. The stars positive force is it's ability to expand. The negative force is gravity,it does not want to let it expand it wants to reduce the stars size, this happens to all astro bodies. But when a star of great magnitude, such as one with ten times the mass of our sun.
Gravity focuses greater on such a large object,forcing it to collapes.
So it is a battle the star and gravity. I hope i could of some help, my suggestion to you would be to go to the local library and get book on The fundementals of blackhole,gravity,star and possible string theory. And if you get a chance definetly read about the theory of obtaining the infininte power and energy of a blackhole. Bye for now.