How do Newton's and Kepler's laws apply to galaxies(or galaxy collisions)?

Newton's Laws of Motion

If Kepler's laws define the motion of the planets, Newton's laws define motion. Thinking on Kepler's laws, Newton realized that all motion, whether it was the orbit of the Moon around the Earth or an apple falling from a tree, followed the same basic principles.

i would think it's food chain

d.7.5cm is your answer