Wednesday, October 12, 2016

Extensions to SHM in AP-Physics

It is very important that students in AP-Physics classes be pushed to go beyond the usual curriculum material. We owe it to them to conduct harder labs that would push their thinking and analysis limits.

What to do?
As an option that instructors may choose is to extend regular topics to include situations that are different, unusual, or simply more difficult to arrive at definitive answers. For instance, this year, the subject of Simple Harmonic Motion (SHM) was expanded to include the following extensions and twists.

Example 1: [From Simple Pendulum to Compound Pendula]
In this case, the students are handed rectangular wooden blocks and triangular prism wooden blocks and are asked to make predictions regarding these compound pendula. For instance, what would the period be? Will it depend on mass? Will the amplitude matter? How would this kind of pendulum compare to a simple pendulum? etc.

Student was using her mobile device to measure the period.

Example 2: [From SHM to Damped Oscillations]
In this case, the students are presented with a situation where the would collect data involving a spring-mass system whereby the mass is oscillating in water as opposed to in the air as is usually the case in regular labs. The following images show the lab set up and the results of the activity.

Closing Thoughts:

Student appreciate being challenged, especially in courses such as AP-courses where the expect an added level of difficulty and rigorousness. The added benefit of such extensions is that it offers instructors the chance to detect and address any lingering misconceptions related to simpler items from the regular curriculum. This is bourn by the fact that students who have gaps in their understanding of regular material, this gaps are bound to surface in these new challenging settings. And as such, these challenging additions may serve as a safety valves that enable us, educators, to address less understood concepts in our main curriculum.

Thank you for taking the time to read this blog entry and I hope you would add your own comments on the subject matter. What kind of extensions do you have your own students contemplate and go through?


  1. Great stuff here, Nadji, thanks for posting! I think all of these are really useful. Did the students brainstorm even crazier extensions? I wonder how they'd deal with a pendulum where the center of mass isn't in the body of the object (like an L-shape).

  2. (another post because I forgot to hit "notify me", sorry)

  3. Hi Sidi. Simply put: I got ripped off on Physics (and Physix). I was a very good students in highschool--just loved every subject. Until I met the teacher who sucked the joy right out of me. And I didn't take anymore Physics after that. So I can't comment on the science here--or say how I would extend the experiments--but I applaud your dedication to great teaching!