Relative Motion in a Subway Station
Relative Motion in a Subway Station
If you are on a subway train in a subway station, you can see people standing or sometimes walking in the aisles of another train; your train or the other train might be moving in either direction. Sometimes it is hard to say what is moving! This means that the motion of a body always depends on a particular frame of reference. Galileo was the first person to formalize this concept, which is known as relative motion.