Day 10

Block 5,6 (Physics 1,2)

Today we finished up blogging our lab reports, and I am worried that I might have gone a little heavy on the direct instruction.

My approach was to have them finish their data analysis and start their conclusions, but I took an approach that made the analysis about expectations for our process in the classroom. Rather than extolling the virtues of analysis and its role in science, I decided to simply tell them what they must deliver every time they take data

In short this is what I expect

  • A data column/table with the independent variable as the left-hand column and the dependent variable as the right-hand column
  • Data must be represented as a graph
  • The axes of the graph must be labelled with variable name and units
  • The graph must have the title [Dependent Variable Name] vs. [Independent Variable Name]
  • The slope and the intercept must be calculated and the equation of the line must be written in slope intercept form
  • the letters “y” and “x” should not be used, but rather variables that recall the variables they measure
  • In the data analysis there should be a section entitled “What the slope means” followed by a physical interpretation of the slope that does not rely on the words “rise over run”
  • In the data analysis section there should be a section entitled “What the y-intercept means” followed by a physical interpretation of the intercept that does not rely on phrasing like “where it crosses the y-axis”.
  • The physical model should describe the relationship between the independent and the dependent variable a linear, exponential, power, etc

I had some criteria for the conclusion, and one of the areas of focus I had was sources of error. I told them that they were not allowed to ever use the words “human error” or “measurement error”.

The nice thing about inquiry based labs is that students make plenty of mistakes. I told them to draw on that wealth of experience. It was great because I actually (finally!) got some real answers such as “For our last trial we lost count of the marbles so we estimated how many we thought we put in there.” or “Our tables were not level which made keeping the bridge still really challenging.” For this lab, we are keeping things qualitative but we will definitely have a quantitative component in future labs.

Block 1 (AP Physics C)

What have my AP students forgotten how do to? Thanks to our online multiple choice exam grading system, I can use item analysis to find out.

The short answer is, anything that involves Free Body Diagrams and Angles.

Given that most of my blocks are non-AP physics I decided to recycle lab materials from the modeling spaghetti bridge lab and do a Three Act Physics Lesson:

To summarize, students basically saw right away that the goal was to figure out the tension the spaghetti when it breaks:

Enclosed are a couple of snaps of what they are up to now.

IMG_2258 IMG_2259

After they finished this, I need an inclined plane challenge, which I think I already know how to do:



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