Answer:
c. gravitational attraction between the sun and earth
Low mass: Live for billions (trillions?) of years. The first low mass red dwarfs in this universe still haven't died off yet, so we aren't completely sure what happens when they "die."
<span>Very High Mass: Run through their fuel exceedingly fast. *Die* relatively quickly (in the range of tens to hundreds of millions of years instead of billions and beyond) and go out with style, Supernova that will leave behind a neutron star (the *kind of very high mass stars" end this way) or a black hole (the *very very high mass stars* end this way.)</span>
<span>Strong nuclear forces hold the nucleus of an atom together. Weak nuclear forces are involved when certain types of atoms break down.</span>
Haven't taken physics but I would assume if her friend is standing in front of her that you would add up the speeds and get 30 km/hr.
