Speed of sound

The speed of sound laboratory began with steady rain. By 9:00 the rain had eased to a light enough rain to be able to hear an echo. The eight o'clock section then ventured out to find sheltered echo launch locations from which to make measurements.

The extra time provided an opportunity to cover the speed of sound in detail including an analysis of how far sound can travel within the span of human reaction times. During the fastest double click of the stop watch, 0.09 seconds, sound travels 31.5 meters - the length of the A building.

The dry bulb temperature at 8:00 was 25 Celsius, the wet bulb was 25 Celsius, thus the wet bulb depression was 0 Celsius. The humidity was 100%. There was fog on the ridge and rain in the air, little wonder that the humidity was saturated humidity.


The rain also permitted coverage of how the laboratory works and a short primer on significant digit

The long echo to the women's dormitory. Tough to time at the distance.


 The students sat this one out while I stood in the light rain and clapped. 



 The core gear for the laboratory.


The class gathered under the eave of the administration building. I would spend the day wet due to two outdoor laboratories and a forest hike in ethnobotany, I felt there was little educational value in having the students also wet all day.


Darla clapped for echoes off of the cafeteria.


Reliann and Darla study the data gathered.


As I often do for laboratory nine, I sketched out the xy scattergraph and ran a preliminary best fit line to determine whether the y-intercept might prove problematic. Laboratory nine really benefits from the use of the LINEST function with the y-intercept set to zero. LINEST was dropped from the fourth edition of the text. The students could not determine when to use SLOPE, INTERCEPT, and when to use LINEST. My statistics alumni were also confused as they had not used LINEST. Still, LINEST often produces a smaller error against the expected value than SLOPE>


 Darby walking back from the bookstore.

 Person has a go at clapping.


Darby returns.

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