Physics Lab Ideas - Structure or No?

In #science

Over the years I have taught introductory physics labs and I have seen that most “canned” labs offer very little to the student in the form of learning. I summarize them as “here is something known quite well, and you are going to measure it badly”. Labs measuring the acceleration due to gravity, <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>g</mi></mrow><annotation encoding="application/x-tex">g</annotation></semantics></math>, falls into that category. How do you improve these sorts of labs? I have a few ideas.

  1. choose problems where the answer isn’t known or known well
  2. push the limit of a particular simple case into the area where the simple case breaks down
  3. have the students design the lab themselves to answer a question

So, for the case of the acceleration due to gravity, put it as a model comparison problem:

  • Model 1 = objects fall with a constant speed
  • Model 2 = objects fall with a constant acceleration

Then you give objects to the students such as pennies, packing peanuts, coffee filters, marbles, etc… Some objects might be best explained with Model 2 while others with Model 1. Neither model may describe some perfectly. How can you tell? Having the students design the resulting tests makes the laboratory experience a lot more interesting. I’ll add a selfish note that it makes the labs more interesting for the instructor as well.