# Conservation of Energy Rocks

Somehow, when I am teaching Physics, I feel like I am holding out on my students until we get to work and energy. Once we start problem solving using energy rather than dynamics, there is a certain elegance, and a much greater portability – principles of energy are quite general, and can be applied outside the Physics classroom much more readily than, say, Newton’s Laws. Central to using W&E are the law of conservation of energy and the Work-Energy theorem. In order to illustrate the law of conservation of energy in class today we took a video of a pendulum and dropped it into Tracker. Here is the result:

I love the way this came out, showing the kinetic and potential energies swapping back and forth. This was a very easy, and very visual demonstration.

## 5 thoughts on “Conservation of Energy Rocks”

1. ed Post author

The ol’ bouncing ball is good too – adds efficiency to the picture, and a discussion of how the ball behaves as a spring.

1. Dan Fullerton

Hi Ed! Pleased to meet another physics blogger! I’ve added a link to your blog on http://aplusphysics.com/flux, and saw that you were looking for a discussion forum to add to your site. If you’d like, you’re more than welcome to use the forums at aplusphysics.com — I can easily tailor categories and permissions for you and your students if you’re so inclined.

Best Wishes,
Dan

1. ed Post author

Thanks – I added Physics in Flux to the blogroll. And I’ll add a “contact me” somewhere đź™‚

2. Shawn Cornally

Welcome to the fold! Your blog is being passed around twitter, so I’d be expecting some attention from the WCYDWT folks!

I love the post. I’ve played around with teaching energy conservation first, and it has worked really well. I teach mgh and .5mv^2 right away, and then we fill in the details as we move through other unites. The kids seem to get a much better handle on the abstractions of work and energy this way, but I haven’t done any solid research.

Thanks for the post!