Energy-first approach to introductory physics

[mjordan2nd]

I've heard that some professors choose to teach introductory physics by introducing energy and conservation of energy before anything else. This seems pedagogically convoluted to me. Could someone point me to a source that does this so I can get a better understanding of how it's done?

 

[Simon Bridge]

I've heard that too - however, whenever I've investigated I've only found it at the tertiary level.
In other words, the conceptual framework has already been laid down in secondary school ... given that you should be able to see how an energy-focussed college freshman course could be constructed.

Have you seen:
http://l10.cgpublisher.com/proposals/362/index_html

 

[mjordan2nd]

I got to that point, but was not able to access the paper.

Thanks for the reply!

 

[Simon Bridge]

Paper has not been submitted - it's a presentation ... you could ask the author or see if the slides are available.
However, my reading of the abstract is that it is aimed at freshman college level, or people who have completed secondary school but may need a secondary-level refresher.

You could probably start with gravitational potential energy close to the surface of the Earth - work becomes the change in potential and you can also relate that to kinetic energy and speed. The slope of the potential gives the acceleration etc. Build concepts experimentally... move on to other kinds of potential. You end up with almost a constructivist approach.

 

[mpresic]

I consider the energy-first approach as more natural. Energy is a scalar and using energy first, we can delay teaching vectors for solving 2-D problems a little longer, (albeit probably nor more than a few weeks at most). The harmonic oscillator equation from energy conservation is a standard integral treated is a good high school calculus class rather than to "guess" a solution to the differential equation. I have often thought when I was learning this > 40 years ago, suppose you are a bad guesser.

Given that my teaching experience has always been a TA and not instructor for the course, I never was given the autonomy for rearranging the lesson plan. I noted many years ago, I used a calculus textbook that started with integration rather than differentiation. Now that felt unnatural.

 

[Intrastellar]

I do not know if this counts, but Feynman introduces conservation of energy before first talking about forces, he does talk about energy conservation in more detail late though.

http://www.feynmanlectures.caltech.edu/I_toc.html