RipStik acceleration and measuring gravity

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 marbles in laboratory two had already established what a slowing object looked like on a time versus distance graph

I overlooked wearing shoes and was unable to generate the accelerations that I have been able to generate in the past. Zoris leave one acceleration challenged on a RipStik. I only attempted a two post acceleration. I continued to a third post, but I was decelerating due to instability by that point.


time (s) distance (m) velocity (m/s) acceleration (m/s²)
0 0 0 0
5.39 4.6 0.85 0.16
8.55 9.2 1.46 0.19


In the past overall the acceleration held close to 0.20 m/s². The smaller values above may also be a result of my choice of foot wear.


The arc of a ball activity was not done except in an extremely abbreviated format wherein I tossed a ball along a juggling arc in front of the board and traced the arc to show that a parabolic curve as a plausible shape for the path of the ball in the air.

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, and then move outside to accomplish ball drops of 400 cm and 500 cm.

 
Raynard holds a super ball while Joe-Ann steadies the meter sticks.

This was the second term using the approach of calculating ½t² for the second table. While spring 2011 only graphed the second table, that change obscured the curved nature of data in the first table. Thus, as per the present draft of the fourth edition of the text, both graphs are back in laboratory three. 

Lewis drops and times, Jackleen holds the meter sticks
 
The new stopwatches appeared to make measurements easier for the sudents.

Sucyang drops and times, Merseny holds the meter sticks, Tracy records data



Jeremy drops and times, Nayleen holds meter sticks, Joyleen steadies the bottom meter stick

Comments

Post a Comment

Popular posts from this blog

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

Experimenting with the PlantNet and iNaturalist apps

Image
The application of image recognition technologies as the back end to botany apps is providing increasingly relevant search results. Over the recent winter break I began looking at whether the apps now available might be useful to the ethnobotany class here on Pohnpei. Some apps had a more regional focus in the past and were better at north american or european plants. Pohnpei has a both unique indigenous plants and many introduced plants from around the world -  a challenging environment for any image recognition system. A student working with a plant identification app for the first time My criterion was that the app had to be appropriate for use in my classroom. The app could not contain advertising and the app had to be free, my students typically do not have the ability to pay for an app. The app would also have to be fairly small as my students often use phones with limited memory and processing power. I settled on PlantNet and was impressed with the ability of the a...
Read more