I like to send people into elevators with scales that they can stand on while traveling up and down. It’s a great exercise because they get to see some physics that they are actively a part of. At the same time, it becomes a nice conversation piece as different, surprised observers come in and out of the elevator we’ve turned into a laboratory.

I spent some time myself on the scale on an elevator, and I made a point of recording a round trip from the bottom floor to the top and back again.

I think it’s really important for you to know that this scale, like many, is a little sticky and is probably only trustworthy within a pound or so. That is, I think anything that between 158 to 162 pounds is really the same. Keep that in mind as you watch.

You can watch the video as many times as you’d like and look for connections between the motions of the elevator and the readings on the scale. What patterns do you see? What do you think the cause and effect relationships are? In other words, what makes the scale reading change; and what does not cause the scale to change from its normal reading?

This might inspire other experiments you can do on elevators. Does it matter if the person is bigger or smaller? If the elevator is faster or slower? What if you were on a roller coaster or other ride that might move you in more drastic ways? Can you model how the pushes and pulls on the rider would change?

Epilogue:

I made a new video, this one without captions but a smoother responding scale. I think it could be useful for another round of observations, or even as a place to start:

Epilogue again!