RipStik for vector exposition and addition

Vectors are fun. I sat in the computer laboratory staring at section 8.3 of Larson's Algebra and Trigonometry text. Nothing I saw on the page looked like fun. My mind wandered to my RipStik. And then in a flash I knew I wanted to fling a ball at a right angle from a moving RipStik and use the radar gun to get the ball launch speed. The RipStik could be timed across a distance with a stopwatch. 


Kenneth used the radar gun to obtain the ball launch speed.


Marla timed the RipStik over an 800 cm distance. She obtained a time of 3.28 seconds for a
RipStik velocity of 243.9 cm/s.


Maggie handled the RipStik riding and ball launching, freeing me up to photo-document the experiment.


Lecture then proceeded on the sidewalk. Note that the radar gun measured in kilometers per hour. 31 kph was 861 cm/s. The ball was thrown perpendicular to the path of the RipStik directly at the radra gun, but the path over the ground, and the net velocity vector, carried the ball towards the Araucaria pine. The i, j notation is upside down so that it would be right side up for the students who had settled onto the faculty building stairs.


The class then returned to the classroom to provide some definitions for magnitude, direction angle, and the unit vectors. 

The day before I sneaked a couple vectors onto the board when covering a trajectory equation in section 7.3.


Vectors are fun, especially when is able to play with them outside!

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, o...
Read more