Paper Tube Experiment

Contributed by Mena Yang

Introduction:

I would like to call it a paper tube challenge.

 How to drop a paper tube in the air, and let it stand still on the table? 

Materials:

A paper tube

Procedure:

1. Drop a paper tube vertically to see whether it can stand still on the table
2. Drop a paper tube horizontally to see whether it can stand still on the table 

Result:

The possibility to let the paper tube stand still on the table by dropping it horizontally is much higher than the possibility by dropping it vertically. 

Physics concepts and questions: 

(Institute of Physics CAS)

The first graph on the top conveys the motion of the tube if we drop it vertically. Since the motion is complex, we focus on the motion of the blue dot (center of mass). After hitting the ground, in this case, the blue dot is getting lower and lower, so the speed will increase until the tube lies down on the table. 

The second graph on the bottom shows the motion of the tube if we drop it horizontally. We also focus on the motion of the blue dot. After hitting the ground, in this case, the blue dot is getting higher and higher, so the speed will be smaller. Then there is a possibility to let it stop spinning, and stand on the table vertically. 

Citations:

Institute of Physics CAS, 2020, “Do not throw the paper tube. Draw on it. Your friends will……” Institute of Physics CAS’s Official account, Wechat.