critical thinking

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, \(g\), 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.