Copyright © Michael Richmond.
This work is licensed under a Creative Commons License.
Displacement and Velocity
- Displacement is the vector difference between the ending
and starting positions of an object. It may be very different
from the distance the object has travelled along the way.
- Velocity is the rate at which displacement changes with time.
It is a vector, too.
- The average velocity over some interval is the total displacement
during that interval, divided by the time.
- The instantaneous velocity at some moment in time is the
velocity of the object right now!
- Instantaneous velocity is the derivative of position with respect
to time.
- Speed is a scalar, which describes the total distance travelled
by some object during some time interval. Speed is sometimes
equal to the magnitude of a velocity vector, but not always.
- Use some common sense when you have finished a problem: look at the
answer and ask yourself, "Is that reasonable?"
Viewgraphs
Copyright © Michael Richmond.
This work is licensed under a Creative Commons License.