Showing posts from January, 2011

Acceleration of gravity

Laboratory 032 involves timing the fall of a ball to determine the acceleration of gravity g. The students drop a small superball from heights of 100 to 300 centimeters inside the classroom.

Sylvia holds a super ball while Caroline and Tracy Ann steady the meter sticks. Irene looks on.
Laboratory 032 now builds on two earlier activities that during a regular school usually occur on Monday and Wednesday respectively. The first activity was a plot of time versus distance for an accelerating RipStik.

Angie holds the meter sticks, Brilinda drops and times.

The students graphed the time versus the distance for the RipStik and found a non-linear relationship (curved line) between time and distance for the accelerating RipStik.

Jermis holds the tape measure as Fritzgerald releases the super ball.
In the second activity, the arc of a ball, the students explored whether the trajectory of a ball might be related to a parabola. A quadratic equation was presented as the underlying mathemati…

Plants of Pohnpei Ethnobotanical Garden Visit

The SC/SS 115 Ethnobotany class visted the Pohnpei Traditional Plants ethnobotanical garden at the Pohnpei campus. This term Totoa had Ben lead the presentation. As I had explained to the class, ethnobotanical knowledge resides within a cultural and linguistic context. Having Ben present the plants in the language of their usage on the island on which the field trip was held was most apropos. The students had the opportunity to experience ethnobotany as an ethnobotanist might on an initial visit to a foreign culture.

Toa provides an introduction to the garden, explaining the purpose and intent of the garden as a place of learning and cultural conservation.

The class was by and large attentive. The loss of knowledge continues to be evident term-to-term as fewer and fewer students are able to name the plants of their islands and fewer still know the uses. A couple days later only a single student recognized kadiring in class. 
The class consists of twenty-eight students, three from Yap m…

Artzooka: Minions

My son has been much taken with Artzooka. What was once trash is now treasure, much to the consternation of his mother. His latest effort is Minions.
 Bottle caps form the eyes, the body are toilet paper tubes. A women's razor was repurposed as a nose.

The arms are corks from Wollersheim winery. These are a rare treasure out here on Pohnpei and I expect his supply is exhausted with these three minions.

Each minion is armed with a blue pan.

Arc of a ball

Exercise 031, the mapping of the parabolic arc of a ball, was modified this term. I wanted more data points than the exercise traditionally generates. Last fall I hit upon the idea of keeping the arc wholly on the white board and using an army of students with markers to capture the ball arc data points.

x (cm)y (cm)y theor (cm)-207015.36-2001020.99-1782137.41-1563551.93-1105376.1-786987.98-219499.13229299.04758188.891775038.122440-17.6
I repeated this again this term, although the marks were not as accurate as I might have hoped. I also did not leave enough time to explain the theoretic function, how to enter it into a third column in a spread sheet, and then graph the actual data and the theoretic curve on the same chart in a spreadsheet. With 34 students, checking homework took longer. Although the homework check uses time, it also provides a valuable opportunity to see what each and every student is able to do and not do.
The third column of the table is to include the theoretic…

RipStik Accelerated Motion

In a previous article I shared the use of a RipStik in SC 130 Physical Science to demonstrate linear constant velocity motion. The ability to generate a relatively constant velocity by swizzling at a constant rate on level ground was useful to that demonstration. 
This term the non-linear motion of the rolling ball in laboratory two had already set up the concept of curved lines as changing speeds on a time versus distance xy scattergraph. This permitted me to move directly to data gathering for an accelerating RipStik. This term I was rusty and did not generate the same top end as I have in the past. At the end of the run I simply "ran out" of acceleration capacity.
PillarTime (s)Distance (m)Velocity (m/s)acc (m/s²)one000

Speeding and playing

Over the weekend data was gathered for use in statistics class using Bushnell Speed Radar Gun. Local law enforcement does not have speed guns, although the Sokeh's police had, to the best of my recollection, a speed gun at a couple different times in the past. On Pohnpei state code 71 PC 8-129 specifies a speed limit of 25 miles per hour which is 40 kilometers per hour.

Sitting on the causeway with view to a radar kill shot.
Given that drivers are keenly aware of the lack of speed detection technology, what speeds do drivers choose? The results are in the table below for two locations.

Causeway (kph)Hospital (kph)407430255568603441346130533829305540274632444149396168322935584339313636547728554126443948357861

Lycophyte and monilophyte presentations

Students in SC/SS 115 Ethnobotany gave presentations on the botany and local names of cyanobacteria, lycophytes, and monilophytes.
 Vanessa and Julie Ann present plant names in Kosraean and Pingalapese. Julie Ann noted that the Nephrolepis fern called rehdil in Pohnpeian is actually called neiniko in Pingalapese. Her source for this was Mihner Ioanis, her grandmother.
 Jasmine and Jayheart covered the life cycle of ferns with a well done diagram.
 The life cycle of ferns diagram was one of the better ones I have seen over the years.
 Juanita and Lewis covered fern morphology.

Rolling balls and linear relationships

This spring laboratory 022 was the first of the even "no write up" laboratories. Until this term, student's wrote up every laboratory as a full laboratory report. The reports were then marked for content, grammar, vocabulary, organization, and cohesion. The work load for the instructor, roughly 14 laboratory reports per term, was heavy. With 32 students, the instructor faced hours of grading every weekend, not including work load associated with their other courses. Making the course acceptable to other faculty in the system required reducing the enormous work load.
The eight o'clock class on a wet morning rolls the ball, students lined up to locate the ball at one, two, three, four, five, and six seconds.
This term only the odd numbered laboratories are written up, which cuts the number of laboratories to be marked in half. The unanswered assessment question is whether the writing benefit will be retained. The complication is that only grammar has ever shown a stati…

Libraries must always change

Since working on the vision statement for the LRC in 1993, I have always felt that libraries should be the information heart of the campus. Today's library is not necessarily contained within a building as evidenced by Greene, Roser, and Ruane's The Anywhere Library. As a preparation towards serving on an ad hoc committee at the college, I felt it prudent to bring myself up to speed on the changing role of libraries in the digital age and the implications for the college LRC.
I might not tackle the Association of Research Libraries 92 page scenarios for research libraries in 2030 (although I did download it), but there is an abbreviated article on it in the Chronicle.
I did enjoy the 2003 "What libraries can learn from bookstores" but I realize that few college libraries are prepared to serve coffee and cinnamon to their patrons. Still, thinking in terms of "what if the library had to …

Underage RipStiking

The packaging clearly says for children eight years old and older. And a best effort is made around the house to ensure that riders are of the appropriate age. In theory a younger rider will have a lower body-to-board weight which ought to lead to less ability to control and propel the board. Someone forgot to tell one of the denizens of our domicile that they were too young to learn to ride, let alone to ride a RipStik.
And not just a little younger, fifty percent younger. Four years old. And ripping the new arrivals parking lot at the airport.
Yes, she is not wearing the latest from Fallen. Those are zoris, flip-flops for those living to the east of the international dateline. Learning to ride, to "wiggle" as she says, without coming out of your zoris, let alone remaining upright, is a serious skill set to master.
Meanwhile, also enjoying the smooth ride provided by Penta-Ocean were pair riders.
No RipStikers were harmed in the process of obtaining of these images!

In a nod to…

RipStik in physical science: linear motion

To demonstrate linear motion while retaining some modicum of attention span from my social media saturated students, I rode a RipStik along the sidewalk in front of the laboratory. The activity is built around the linear relationship between time and distance for an object moving at a constant velocity. Thus my goal is to retain a constant velocity over the 36.9 meter distance.

Time (s)Distance (m)Pillar-to-pillar velocity (m/s)Acceleration (m/s²)0.000.00



Saturday afternoon was sunny with a strong breeze running off of the ocean. Saturday was also the day a good friend and long time colleague was interred on Kosrae. Had he been a drinker of sakau, I might have had a circle of partners to join over a cup and talk story. He was not, however, a partaker of the slimy concoction. Over the years I had known him, outside of work he kept to his home life.

With his entire family over on Kosrae for the burial, I felt a sense of emptiness. The past thirteen months has seen a number of friends cross that final frontier. Benson, Iris, Ahser, Wilson, and now Harvey. Not being able to be at his graveside mourning, I did what I always tend to do when loss hurts. I ran. I ran down the hill. Down to the river. And I kept on running.

From the start  at 14:44 I ran slowly in the heat of the afternoon, not reaching The Village until just after four. The Madolehnihmw border slid past me at 17:11 and I reached the ESDM school at 17:31.

Sunset finally ended m…


The ethnobotany class includes work on the Palikir student learning ethnobotanical garden. The garden is now being weed-whacked by the grounds crew at the college. As a result the course has acquired more rakes and hand cultivators and shifted from grass whacking to generalized cleaning.

The class started with a walk-though introduction to the plants in the ethnobotanical garden. Identifying the plants and their uses is the core to the final examination.

Cleaning around the Saccharum officinarum Hertin mans a rake

Density of soap

Laboratory 01 in SC 130 Physical Science focused on the linear relationship between volume and density for soap. Harmony beauty soap with a density greater than one gram per cubic centimeter was used along with Ivory soap with a density of less than one gram per cubic centimeter. The soap was carved into square chunks so the volume could be calculated from length × width × height.
Carving the soap in a rectangular chunk
The class began with the Freeman Dyson quote:
For a physicist mathematics is not just a tool by means of which phenomena can be calculated, it is the main source of concepts and principles by means of which new theories can be created... ...equations are quite miraculous in a certain way. ... the fact that nature talks mathematics, I find it miraculous. ... I spent my early days calculating very, very precisely how electrons ought to behave. Well, then somebody went into the laboratory and the electron knew the answer. The electron somehow knew it had to resonate a…