Question
Andy was driving east with a velocity of 2 meters per second (m/s) relative to the ground. While he was driving, he noticed that he was approaching a road sign.
image.png
Which statement correctly describes the motion of the road sign as seen from Andy’s frame of reference?
The road sign appears to be moving away from Andy.
The road sign looks like it is moving toward Andy at a constant speed.
The road sign looks like it is moving toward Andy faster than he is moving.
The road sign appears to stand still relative to Andy.
image.png
Which statement correctly describes the motion of the road sign as seen from Andy’s frame of reference?
The road sign appears to be moving away from Andy.
The road sign looks like it is moving toward Andy at a constant speed.
The road sign looks like it is moving toward Andy faster than he is moving.
The road sign appears to stand still relative to Andy.
Answers
GPT-5 mini
"The road sign looks like it is moving toward Andy at a constant speed."
Reason: the sign is stationary on the ground (0 m/s). Relative to Andy (2 m/s east), the sign's velocity = 0 − 2 m/s = −2 m/s (toward Andy), i.e. it approaches him at 2 m/s.
Reason: the sign is stationary on the ground (0 m/s). Relative to Andy (2 m/s east), the sign's velocity = 0 − 2 m/s = −2 m/s (toward Andy), i.e. it approaches him at 2 m/s.