Relative Velocity

Today, I experienced a nice demonstration of classical relative velocity.

While driving in the mountains, I started to pass a car that was in the lane to my right. To my left, I noticed a railing that had a lot of evenly spaced struts.

I was probably going about seventy miles per hour, with respect to the ground and the railing. In my peripheral vision, the struts of the railing flew past me on my left, giving me a sense of how fast I was moving.

As I was passing the car, it’s motion on my right was much slower, with respect to my vehicle. (It was probably going about fifty-five miles per hour, with respect to the ground.)

So, as I continued to pass the car, I could see myself pulling ahead of the car, moving at about fifteen miles per hour, with respect to the car. At the same time, I could still see the struts of the railing, which let me know that I was still moving at about sixty-five miles per hour, with respect to the ground.

It was fun to see the difference in speeds while looking at both the railing and the other car.

Yes, realizations like this often catch my attention!