Answer:
If you look at the way the earth orbits the sun you will see several physics theories and systems at work. The earth maintains a constant velocity that allows it to keep from falling into the sun's massive gravitational pull, and while the earth is revolving around the sun, it is rotating on its own axis, which gives us our tides (the moon also plays a part in the tides). Also, if the sun were to suddenly gain or lose mass or gravity the earth would catapult into nothing and we would freeze, this is just one small little example of how physics is related to planetary science.