Posts

Showing posts from August, 2016

RipStik acceleration

Image
This term tight time frames did not leave enough time for multiple runs or practice runs. Based on recommendations from spring 2016 I went with a 100 cm interval to 800 cm. In this way I was mimicking the RipStik acceleration run of fall 2015. An attempt to keep the first 100 cm over 1.29 seconds left me unstable, I never fully recovered and lost balance post 800 cm. There was insufficient time for a second run, perhaps more time ought to be devoted to this, but the lack of time was due to review coverage of the Friday quiz. Perhaps that coverage could be reduced to provide more time for multiple runs on the sidewalk, then the smoothest run could be chosen.


Zero was at the post next to the intersection, above I am marking 100 cm


The marks for 100 cm and 200 cm. Perhaps there is a need to try to the monotonically increasing distance model: 0, 100, 300, 700, 1200. The catch is that the sparcity of the points could lead to loss of the sense of a parabolic curve. Perhaps a 50 cm timing ma…

Box and whisker plots in Google Sheets

Image
And then everything changed. For the first time since the loss of Gnumeric a spreadsheet was displaying a box and whisker plot. To back up to the beginning, MS 150 Statistics was built around spreadsheets. Students in the course were not statistics majors and the overwhelming majority were not in a scientific field. Most would wind up working on office desktops for which they would not be an administrator. Downloading R would not be an option and R would be steep learning curve for some for whom computers are an unfamiliar technology.

Spreadsheet based statistics, for all the faults and potential for error, would be at the center of the course. The use of Ubuntu in the classroom meant using LibreOffice.org or Gnumeric. Gnumeric provided the capability of including box and whisker plots. A change in computer laboratory technology to Microsoft Windows five years later saw the use of Gnumeric on Windows - until Gnumeric stopped supporting Windows. A further change of my work top to OSX f…

Monilophyte and lycophyte hike

Image
Fall 2016 I opted for an altered start to the monilophyte hike. On Tuesday I had announced that class would start from the agriculture classroom. On Thursday I picked up moss with spore capsules from the east end of campus prior to class. After I drove down to the agriculture classroom, I searched for and found Nostoc in the driveway. I began in the shade of the trees across from the classroom with an introduction to the Nostoc and the moss. I also distributed the seedless vascular plants of Micronesia hand out. The handout includes names from across Micronesia, this particular post uses only the Latin and Pohnpeian names.


The day was intensely sunny. Post El NiƱo there was absolutely no Lycopodiella cernua to be found. Two factors may have been at play. One, there were grass signs of harvesting, probably for decorations. Two, the drought of earlier in the year may have impacted the population.


 Davallia solida, ulungen kieil.


Asplenium nidus, tehlik.


 Huperzia phlegmaria, limpar.


 Hu…

Linear Velocity of a RipStik, Students, and Rolling Balls

Image
I opened the week on linear velocity with the introduction of a blank time versus distance graph on the board. Then I used the LRC to F2 sidewalk to roll off a 202 cm/s run over a 3000 cm course.


I shared the data and made a sketch graph at the end of class on Monday.

Wednesday I used the Monday data to distinguish between an average and instantaneous velocity. Then I had the students measure their walking speed. I placed paper strips at the LRC and had the students walk from A101 to LRC and back, a 24200 cm round trip which was timed. The students ranged from around 90 cm/s up to around 120 cm/s.

Thursday I went with the rolling ball approach, fixed distances, and the diagonal table layout. I passed out a diagonal data entry sheet at the start of class to guide the students.



The first run, the "slow" ball run, was attempted at 100 cm increments out to 1000 cm. The fiberglass tape measure has made measurements so much easier. White chalk marked 100 cm increments, blue was 20…