Question

Leona throws a baseball 10.0m [E] to her teammate Nikki. Nikki throws it back to Leona. The entire flight of the ball took 5.5s. What is the average velocity of the ball?

Answer 1

Velocity = (total displacement) / (time of travel)
in the direction from start to finish.

Displacement = (distance between the start-point and end-point,
regardless of the route traveled from start to finish)
in the direction from start to finish.

The ball started with Leona and ended with Leona.
Displacement is zero.

Average velocity = (zero) / (5.5 s) = zero .