Physics of playthings: mass versus velocity for flying disks

With no laboratory scheduled for this week, the class will be exploring the physics of playthings. Failure is an option, and the less I know about the system the better. In Playthings I asked the class if mass will be related to velocity for a flying disk. The consensus appeared to be that more massive disks should be faster - within reason. These are toy disks after all, not discus disks.


A set of disks including a flying ring were available ranging from 33 grams to 172 grams.

Alexander, Kiora

The students chose a ten meter throwing pitch just north of the generator.

Sanjay, Alexander

Groups of three to four were necessary: a thrower, a catcher, a timer, and a data recorder. One group had the timer record data.


After data was gathered, I entered data from the three groups into a single table to perform a meta-study. With an r of 0.182 for a linear regression, there was no relationship to speak of. 


This was confirmed in a post-hoc analysis. 


A slope of zero is within the 95% confidence interval. The p-value of 0.46 is not significant at alpha 0.05. Velocity is related to the speed of the initial throw, not the mass. Failure is always an option. And in this case this is a result that I have considered intentionally designing into the course in the past. Sometimes there is no relationship. If every single laboratory leads to a relationship, the students might be left thinking that everything is always related. To have a system with no relationship is potentially quite valuable. 

Rosie-Rita, Sean, Alexander

The wind was not a significant factor today.

Tommy, Rosie-Rita, Alexander, Kiora, Sean, Jocela

Joe Scott throws the green Frisbee® golf disk

Sanjay, Kiora, Jocela, Tommy


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