- The following equations of motion are valid only when…
- acceleration is constant and
- motion is constrained to a straight line.
One dimensional equations of motion for constant acceleration
||v = v0 + at
||x = x0 + v0t + ½at2
||v2 = v02 + 2a(x − x0)
||v̅ = ½(v + v0)
||initial displacement (the displacement at the beginning of some event)
||final displacement (the displacement at the end of some event)
||initial velocity (the velocity at the beginning of some event)
||final velocity (the velocity at the end of some event)
||time (the duration of the event)
- The signs on quantities should be…
- the same if they act in the same direction
- opposite if they act in opposite directions
- The choice of which direction is positive and which is negative is arbitrary.
- The laws of physics are isotropic (are not affected by your choice).
- Make your decision and stick with it. (Be consistent.)