Acceleration day two

Acceleration day one left open two possible equations that both fit the data, with the exponential reporting a higher coefficient of determination than the quadratic. Day two is intended to reproduce the left side of the curve. In keeping with last term, the sidewalk is marked in three meter segments. I wore my Hoka Mach 4 shoes as those provide a better board grip than the Hoka Challenger 7 series shoes. As long as the Mach 4 shoes are dry, all good. The complication in my first trial run was insufficient speed to reach nine meters. Oops. A second practice run with more pump put me over the nine meter mark with sufficient speed to make the u-turn at the top. 

Desmos

As with last term, omitting the vertex time helps smooth out the curve. The deceleration was on par with prior terms, perhaps slightly higher at -0.4 m/s² versus -0.3 m/s² fall 2023. I am not clear what the cause of the increased deceleration might be, but that suggests a reason I struggled to obtain the nine meter mark. The board is new last term, not sure why it would be slowing as much as it appears to be. 


Early arrival allowed me to preset the board with the Monday Desmos.


I also preset the board. 


Despite the presents, I was on the sidewalk five minutes later than fall 2023. The runs started at 12:15. On the first run I lost all momentum at the turn-around and came off the board. The second run did not make it to nine meters. I could not get the board up to sufficient speed. Old age perhaps. A third run failed when I missed the three meter timing mark. On the fourth run I slightly overran the three meter mark and nearly came off just past nine, but I eked out two measurements at nine meters and made it back down the course. 

Desmos

The delayed reaction to crossing three meters on the upbound side can be seen in the graph above. I knew the data had issues, but the push to hit nine meters was proving hit and miss this term. The board felt sluggish. Probably just me. 

I then showed that the exponential equation no longer explained the data, but the quadratic equation behaved in a manner consistent with the data. I then used the equation to cover the slope of the quadratic equation as the velocity of the RipStik. 

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

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, o...
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