phy
posted by ami on .
A horse canters away from its trainer in a straight line, moving 140 m away in 16.0 s. It then turns abruptly and gallops halfway back in 5.0 s.
(a) Calculate its average speed.
(b) Calculate its average velocity for the entire trip, using "away from the trainer" as the positive direction.

(a) It travels a total of 210 m in 21 s. Ignore the fact that the direction changes. The average speed is 210/21 = 10 m/s.
(b) The net displacement is 70 m in 21 s. The average velocity is 70/21 = 3.33 m/s