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Motion
Why start off with a discussion of motion as our rst physics topic? There are several
reasons. Certainly motion is very familiar to us. After all, we experience it every day.
Historically, it was one of the rst things studied by the Greeks. To them, there was
the perfect and eternal motion of heavenly bodies, where the gods resided, and the
imperfect motion of earthly objects that eventually had to come to rest. In our more
modern world, we realize that just about everything is in some state of motion. The
earth both revolves about the sun once a year and rotates on its axis once a day. The
air around us is always moving, sometimes ...