Final answer:
As Anita is running to the right at 5.0 m/s and the balls are thrown toward her at 10 m/s, she would perceive the balls as moving to the left at 5.0 m/s. so, option a is the correct answer.
Step-by-step explanation:
The movement of the balls as perceived by Anita, who is running to the right at 5.0 m/s, when balls 1 and 2 are thrown towards her at 10 m/s, can be understood in terms of relative velocity. The relative velocity of an object is determined by subtracting the velocity of the observer from the velocity of the object. Hence, in this case, you subtract Anita's velocity from the balls' velocity, which is 10 m/s - 5.0 m/s = 5.0 m/s to the left. Therefore, as perceived by Anita, the balls are moving to the left at 5.0 m/s.
The relative motion of the balls as perceived by Anita is option a) They are moving to the left at 5.0 m/s.
This is because Anita is running towards the right at 5.0 m/s, and the balls are thrown towards her at 10 m/s. Since the balls are thrown towards Anita, their motion will appear slower to her compared to an observer at rest. Therefore, the balls will seem to be moving to the left at 5.0 m/s relative to Anita.