Final answer:
In the reference frame of a bicyclist passing by to your right on a sidewalk, you, as a stationary observer, would appear to be moving to the left due to relative motion.
Step-by-step explanation:
When it comes to observing motion, it is important to understand that different reference frames can yield different perceptions of motion. A reference frame is essentially a viewpoint or coordinate system from which an observer measures the properties of objects, like their speed and position. In physics, this concept helps explain how motion is relative to the observer's own movement.
In the scenario where you are standing on a sidewalk watching a bicyclist pass by to your right, your stationary position on the sidewalk is the reference frame for the biker's motion. To the bicyclist looking at you from their moving reference frame, you appear to be moving to the left, which is the opposite direction to their motion. This is due to the relative motion between you and the bicyclist.
Imagine you and the biker are positioned on a two-dimensional grid, like the roads and sidewalks of New York City as described in Figure 3.2, where you must follow a zigzagged path. As the biker moves to the right on this grid, you remain in the same grid location, but to the biker, who is in motion, it appears you're moving to the left.