Average velocity is defined in analogy to average speed. Instead of taking the ratio 'distance traveled divided by time elapsed', one takes the ratio 'displacement divided by time elapsed'. Thus,

Average velocity is a vector quantity, because it is the ratio of a vector (the displacement) and a scalar (the time elapsed).

Symbol: _av; SI-unit: m/s.

Exercise: Position the ball somewhere, and release the mouse button. Click on the ball again and drag it. Display the applet's Data boxes, including the expanded average-velocity box obtained by selecting the Position button. Substitute the values of the displacement = Δ = _f - _i and time elapsed from the Data boxes into the definition above to calculate the x,y components of the average velocity vector for the motion.

Compare your result to the value of _av in the average-velocity Data box.

Also copy the value of the average speed v_av from the average-speed Data box. You will need the values of both _av and v_av on Page 3.