APFIVE One-Dimensional Relative Velocity
Train A moves east at a constant speed of 25 m/s, while Train B moves west at a constant speed of 20 m/s on parallel tracks. A passenger on Train A throws a ball with a speed of 15 m/s relative to the train, in the same direction as the train’s motion. What is the speed of the ball as measured by an observer on Train B?
A
40 m/s
B
60 m/s
C
10 m/s
D
45 m/s