# Formulae and Constants

1. Apr 9, 2005

### Poop-Loops

I'm taking my 3rd quarter on phys. in college right now (heat, sound, optics, & fluids this quarter), and I've noticed that neither here nor in high school was the knowledge of constants and formulae emphasized. Basically, you ask for a formula (as long as it's a simple relationship, not the answer to your problem) or constant on a test, and the teacher gives it to you. The reasons given for doing this is that apparently high school physics is hard and people have trouble memorizing them on top of understanding the material. My prof says that in the real world, you can open any physics book and get the info you want anyway, so there's no point in wasting your brain power on memorizing. I totally agree, but does the rest of the physics academic community follow that? I don't want to get to higher classes and suddenly have to memorize 20+ formulae just to be on par with the rest of the class.

PL

2. Apr 10, 2005

Then don't. Use your spare time to look at the derivations of these formulae, then you'll feel happy because you at least understand how such formula about such and such force came into being.

3. Apr 10, 2005

### cAm

On my tests (high school, physics c), we're given any constant/formulae we want. I think it's pretty standard. (doesn't the AP test even give you a big sheet of formulae/constants?)

4. Apr 10, 2005

### KingOfTwilight

A bit off-topic but what the heck...
In Finland we have a 160 page book containing formulas and various constants & other info (friction coeffients e.g.). The book has section for math, physics and chemistry and we are allowed to use it in exams. And I'm a sixth form student now, I dunno if they use MAOL (the name of the book) in universities.

5. Apr 10, 2005

It pretty much should be, as doing marks by just memorizing formulae is nothing constructive at all.

6. Apr 10, 2005

### Poop-Loops

Good. I mean, I remember most formulae anyway, but I don't make an effort to do it. I usually end up memorizing them by using them a lot in homework problems.

Bladibla, that's what my prof said, don't memorize formulae, just understand how you can derive it.

That's a relief, I hate memorizing formulae. Thanks. :D

PL

7. Apr 10, 2005

### SpaceTiger

Staff Emeritus
There's absolutely no question that a good school will emphasize understanding over memorization, but at the highest levels, they expect a certain level of both. There's a famous story about the general examination here at Princeton (I hate to name-drop, but it's probably important for this section of the forums) where a student was asked the value of a certain physical constant, I think it may have been Planck's constant. Anyway, this was a particularly cocky student, so he said "I don't know, but I can always look it up in a book." The professor basically responded, "That is not an acceptable answer".

The reason is that a good scientist should be able to do a decent order of magnitude calculation on the fly, because questions will come up in situations where you don't have a book or the internet handy (restuarants are a common place for that). This is especially true of formulae. If I had to look up every formula that I used, my research would be pretty slow going.

8. Apr 10, 2005

But you must relise that formulae are for convenience. So knowing the derivation, THEN knowing the formula is the best way.

9. Apr 10, 2005

### Hurkyl

Staff Emeritus
The way I heard the story was more amusing:

Student: "I can look that fact up any time I need it"
Professor: "That's not true, because you sure need it now!"

10. Apr 10, 2005

### SpaceTiger

Staff Emeritus
The story I was referring to concerned a guy I actually met and recently graduated, so unless we're in the same department, it must be a pretty common occurence on these exams.

11. Apr 12, 2005

### Poop-Loops

Hmmm.... that's bad. My prof rarely shows how formulae were derived. Then again, I'm only taking 2nd year courses....

PL