## Monday, May 28, 2007

### Which constants should students memorize?

High school physics students, specifically.

Some might argue for none. I can see some reason in that. Many think of memorization of any kind as a burdensome task that kills all joy for miles around. Such absolute aversion may be an overreaction to bad instructional experiences from one's own past.

At the moment, I can see some value in having high school physics students internalize five constants:

Gravitational acceleration at the surface of the earth: g = 9.8 m/s^2
Elementary charge: e = 1.6 x 10^-19 C
Speed of light in free space: c = 3 x 10^8 m/s
Universal gravitation constant: G = 6.67 x 10^-11 kg m^2/kg^2
Coulomb constant: k = 9 x 10^9 N m^2/C^2

High school physics teachers all tend to think alike and readily agree on all maters pedagogical. So I'm guessing that if these are the values I think should be memorized, the rest of you agree by default. Am I right?

Anonymous said...

I prefer epsilon naught to k, myself... Other than that, I think that I'm on board. My students always get in a huff about memorizing stuff, but if they do the amount of work with and thinking about the equations (and constants) that they should, it shouldn't be an issue!

Dean Baird said...

I know, epsilon naught will take you further; I just like the simplicity of 9E+9 when getting one's hands dirty with Coulomb's law calculations.

In all honesty, I don't have a dog in this fight. Just had a thought after grading an AP free-response question and seeing that some of my bright students hadn't internalized some "important trivia" (physics constants).

Anonymous said...

Stevie Ray Says...

I prefer using Fg = 9.8 N/kg as the gravitational field strength of the earth at sea level.

If you're so keen on memoriztion, why not have students describe one experiment that could be used to determine the constant in question?

My take, "You can't memorize your way to the solution of a NEW problem."

Out.