Final answer:
Elaine sees different toys as the train moves around the track because of relative motion.
Step-by-step explanation:
Elaine sees different toys as the train moves around the track because of the concept of relative motion. When the train is in motion, Elaine, who is on the train, experiences a different frame of reference compared to someone standing on the platform. This means that the positions and perspectives of objects, including toys, will appear different to Elaine as the train moves. For example, if there is a toy at the side of the track, it may appear to move past Elaine on the train, even though she is not actually moving relative to the train