Force and Motion: Facts. Motion makes the world go 'round. Motion makes the moon go 'round too. In fact, motion makes lots of things go. When we think of motion we often think of cars, bicycles, kids running, basketballs bouncing and airplanes flying.
What are stars made of? Basically, stars are big exploding balls of gas, mostly hydrogen and helium. Our nearest star, the Sun, is so hot that the huge amount of hydrogen is undergoing a constant star-wide nuclear reaction, like in a hydrogen bomb. Even though it is constantly exploding in a nuclear reaction, the Sun and other stars are so large and have so much matter in them that it will take billions of years for the explosion to use all the fuel in the star.
Best Answer: The initial size of the star is what decides. A star is huge, I mean really big, and all that gravity wants to pull itself together (everything attracts). So, the star wants to collapse. But, it creates nuclear fusion, and that is the force that pushes the star out.