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


Comments

Post a Comment

Popular posts from this blog

Plotting polar coordinates in Desmos and a vector addition demonstrator

Image
In an earlier post I noted that Desmos did not directly plot polar coordinates. Not only was I incorrect, but Desmos responded to my blog to correct me! Although I had at some point seen that one could define a function f(x)=3x+5 and then have Desmos calculate f(6), I had not absorbed how this might be used to plot polar coordinates. The above works beautifully . Realizing that I could effectively program Desmos, I applied this thinking to demonstrating how to add two vectors when given the magnitudes m and the direction angles theta. The graph calculates the i and j components for the two vectors and then adds the vectors, graphically displaying the result while also providing information on the magnitude and direction of the vector sum. m1 and theta1 are the magnitude and direction angle for one of the two vectors, m2 and theta2 are the magnitude and direction for the other vector. All four are dynamically interactive and can be changed. The diagram purports to illustra
Read more

Setting up a boxplot chart in Google Sheets with multiple boxplots on a single chart

Image
The  Google Statistics  add-on for Google Sheets can display multiple boxplots in a single chart. The key is the layout of the data. One column should be the variable by which the data is to be grouped, the other column should be the data to be box plotted. Set up the Statistics add-on with the data to be plotted as the variable, and the grouping column as the "by" variable. In this image I had deselected all but the boxplot option, the result was the appearance of the Moment, Standard errors, and Confidence intervals options. The default is apparently a 95% confidence interval for the mean. The result is multiple boxplots on a single chart with a common scale. The new tab that is created also quotes 95% confidence intervals for the mean. Note that as of 2018 the Google Statistics add-on cannot be found by search in the add-ons. In addition, as of May 2018 the add-on no longer verifies, possibly due to the add-on not having been updated since August 2017. One may ha
Read more

Traditional food dishes of Micronesia

Image
Clara, Jennette, and Joanie presented ground hard taro cooked in an umw, effectively a hot rock oven. Pohnpeian: rotama. Pingelapese: sero. Mwoakillese: rodma. Mortlockese: Amahd. Kosrae: rodoma. After cooking in an umw the rotama is pounded with the petiole of a palm frond. Rotama is made from hard or swamp taro, known as mwahng on Pohnpei, mweian on Pingalap, pula in Mortlockese, and pahsruhk on Kosrae. In traditional times on the outer islands the women had primary responsibility for tending the taro while the men handled fishing and climbing tasks. Joesen and Noeleen presented fermented breadfruit from the outer islands of Yap such as Woleai and Eauripik. The raw ingredients were actually brought in from Yap, Noeleen prepared the maare.  The leaf wrap is ti leaf - Cordyline fruticosa. Pauleen, Barnson, Trisha, Verginia, Con-ray, and Maylanda from Kitti, Pohnpei brought in mahi umw, koahpnoair koakihr, and uht sukusuk. Above is breadfruit umw, mahi umw, one o
Read more