Conservation of energy explains that energy can only be transferred between different forms of energy
Well, first of all, I don't think "After the collapse of a nebular cloud ..."
is the first time that "atoms begin gravitating together". Seems to me like
that's what was going on all the time, and it's what caused the nebular cloud
to collapse in the first place.
In any case, once the pressure and temperature at the center get high enough,
you get "ignition" of nuclear fusion, and that's when you first have a "star".
I'm not sure...
I feel ya.
Kepler's laws were enunciated to model in a mathematical way the movement of the planets in their respective orbits around the Sun.
There are three laws of Kepler.
In particular, Kepler's first law states the following:
"All the planets move around the Sun describing elliptical orbits, the Sun is in one of the foci of the ellipse."
Answer:
Kepler's 1st law of planetary motion states that the planets have an elliptical orbit, with the Sun at one focal point of the ellipse.
a. 1st law