An object travels North at #6 m/s# for #2 s# and then travels South at #1 m/s# for #4 s#. What are the object's average speed and velocity?
The average velocity is
The average speed of the object is simply the total displacement divided by the total time. Since the object first moves North for two seconds at 6 m/s, the object is displaced 12 meters to the North.
After moving South at 1 m/s for 4 seconds, the object now has a total displacement of 8 meters to the North.
The average speed then is:
And the velocity is simply the average speed in the direction traveled, North.