Motion Along a Straight Line – Lecture 2 (University Physics I)

In Newtonian mechanics, a reference frame is a choice of:

1. A.The absolute position and absolute time of an event in the universe.
2. B.Which observer is currently moving and which observer is at rest.
3. C.What counts as position zero and what counts as time zero, plus units.
4. D.Which direction gravity is allowed to point during the problem.