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Showing posts from June, 2015

Speed of sound

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Michael Yarofaitoar on the clapping blocks
Measuring the speed of sound deployed the approach taken last spring. The weather cooperated, clouds kept the sun from being too hot, yet rain did not fall. A couple future notes. The key to seeing the clap is start with arms at ninety degrees, boards angled to catch the light from the sky, flat face forward towards timers. The middle of the road is best, less visual background clutter. The clapper should be informed that cars behind them are a "no go" condition as the timers cannot always see the boards against the backdrop of cars. The timers need the pavement and fall hill as a backdrop. The clapper can and should get out of the road when traffic is present. The timers will understand what is happening. The clapper was up near the cement box for the power line to the well, slightly east of the crest used in prior terms. This worked better than I had hoped. I suspect the clapper could be even farther east, but intersection traffi…

Weather station visit

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On Tuesday the physical science class visited the National Weather Service, Pohnpei Weather Service Office as a part of a unit on weather.
Edward, Cherish, and Rofino observe as Wallace explains some of the data displays
The class listens intently
Wallace holds the LMS-6 Radiosonde
The radiosonde unit
Theoretic tsunami arrival times from an earthquake in the south Pacific
IR color enhanced satellite photo of western Pacific ocean
Radiosonde data display
Balloon away, released by Eiko

Eiko Ioanis, on the left, was allowed to release the balloon. Perdania Barry, and Alwin look on
Back inside Sharon Mualia, Edward, Perdania, and Rofino watch the radiosonde data display
Radiosonde data
Chatty Beetle for communicating data as text messages among the outer islands. Satellite based, the messages are received across the Pacific.
A future meteorologist, perhaps, at her workstation.

RipStik sine wave trigonometry

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I introduced chapter six, section four of the Larson Alg & Trig text with twin RipStik runs at two different frequencies. Neither run was timed, I opted to focus on wavelength rather than period and frequency to introduce wave concepts.


I opted to use three sheets of paper end-to-end.

 I then made a low speed pass north side pass, unstable but with the hope for a higher frequency.


My second pass was on the south side at speed but I did not well hold my line of travel. I have learned in the past that moving the paper east helps, but a class was in session in A203, so I did not want to risk disturbing that class.


Hard to see, but the north pass was amplitude 3.5 cm with a wavelength around 42 cm, highly variable however. The south pass came in at about an 80 cm wavelength, also 3.5 cm amplitude.

Pi on a clothesline near the equator

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In MS 101 Algebra and Trigonometry I opened the chapter on angles and radians by introducing a dimensionless measure of angles out on the lawn. I put Seagal at the center and then had Tammy walk the surveyor's wheel around Seagal at the end of a 44 foot long piece of clothesline. I probably should have given the line to someone else to keep the line taut as this would prove problematic out between pi over two and pi radians. Every ninety degrees I took a measurement and placed a student. Hansha was at zero next to the A building generator. Moving counter-clockwise, Patricia was a quarter turn, Maggie opposite Hansha, and Shellany at three-quarters of the circle.

Circle complete, Seagal on center, Natasha and Hansha at zero, Tammy holding the wheel, Patricia up at pi over two. Note that Natasha now has the line.
With Hansha at zero, Patricia was 68 feet worth of arc length away. Divided by 44 yielded the dimensionless 1.55 radians. Maggie was at 145 feet around the circle, 3.30 rad…

Meters per minute of longitude

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In the morning the class worked on finding Binky. This term Binky was at North 6° 54.570', East 158° 09.337'. Binky was hidden in the tall grass at the bottom of a tree down a slope off the edge of campus. This led naturally to the question of just how close to Binky could the coordinates have put a searcher? Put another way, how far is 0.001 arc minutes in meters?

Laboratory seven sought to determine the conversion factor between meters and minutes. The conversion factor would allow one to convert 0.001 arc minutes to meters.

Julie-Ann Ardos with the surveyor's wheel
Spring 2015 I sought to decrease the error by using a more precise conversion between feet (measured by the surveyor's wheel) and meters. Rather than use 100 clicks on the non-metric surveyor's wheel as 30 meters, spring 2015 I went ahead and converted each 30 meter interval into feet: 98, 197, 295, 394, 492, and 591 feet. I then rolled the wheel while holding a crib sheet with the equivalents in feet.

Finding Binky

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During the summer term I introduce latitude and longitude through a discovery learning exercise. I give the students a set of coordinates and a GPS. Other than turning on the GPS and paging to where the latitude and longitude is displayed, I give them no other directions other than "Find Binky!" I do let themknow that when the numbers on the GPS match the Binky numbers, then they should be where Binky is.

Binky, summer 2015
At the Binky hide, 6:27 in the morning
Binky's tree on the right down a slope of Ischaemum polystachyum (paddle grass, reh padil)

Initially there is only confusion, pairs with GPS units walking in random directions trying to see what happens to the numbers on the GPS.

Rofino Roby and Franzy Hetiback study the changing digits
Sharon Mualia comparing the numbers on GPS with those on the paper
Michael Yarofaitoar also comparing the values as he walks in the general direction of Binky
Joemar Wasan with the GPS leads Pelma Dilipy and Cherish Laiuetsou towa…