Acceleration of gravity on day three


The board from Wednesday was intact, so I followed the path I took fall 2022 and used the start of the lab to pull together the last week and half.  I included the velocity versus time graphs, although these graphs appear to remain confusing for the students to think about. 


The above was still on the board from the day before. I would add a velocity line to this graph later.

Jonathan and Athina Viola working at one meter

Morales and Sharla also working at one meter


Mersayes and Ashlen performing drop times from one meter

Mersayes and Ashlen at two meters

Working at four and five meters

Conditions were wet in wind driven rain



Left board by 8:00 section end

Right board 8:00 section end

Acceleration of gravity results

Which value is correct? In some sense these are all correct: each represents the best measurement effort of a particular lab team. In another sense these are all incorrect because none are the known value of 9.78995 m/s² for our location. Yet the reduced acceleration for this location also means the typically published value of 9.81 m/s² is also incorrect. In a class where the a core value is that science is that which can be put a laboratory test, the student's values are the values that the students can know to be true. This is what they can prove. And while none are "correct," taken together the values obtained bracket the published value. 

Harvey and Thevonna taking timings

Jenna and Rizal recording data

Ozimy and Shane measuring drop times from one meter

Ivan holds the meter sticks while Fiji does the drop

Serjean and Kaylem working at two meters

The only change in the board at 11:00 was to rerun the procedure


With the 8:00 data still on the board, the 11:00 data was added. The median value was 10.015 m/s², just two percent above the value cited for this location. Having the results on the board allowed for a talk on the nature of truth in physical science. 

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