# Homework Help: How to chose Prefix?

1. Mar 21, 2014

### SwedishFred

Hi
We are going to have an exame in physichs.. Waves and energy and the teacher demands the right prefix. But what is the prior??

Best Regards

2. Mar 21, 2014

### Staff: Mentor

The right prefix for what??? Your question is not clear.

3. Mar 21, 2014

### SteamKing

Staff Emeritus
Herr Doktor Professor always works for me as a Prefix.

4. Mar 21, 2014

### Staff: Mentor

:rofl:

5. Mar 21, 2014

### majormaaz

Energy usually is in Joules, and you'll usually have problems that have answers of just Joules (J). I've seen other answers with units of kiloJoules (kJ = 1000 J), milliJoules(mJ = 0.001 J) and microJoules(μJ 1mJ/1000).

Waves is a general topic, so I'm just going to be speaking generally about this. Wavelength can be answered with units of meters, but you're going to find nanometers(nm = 1 x 10-9 m) to be a much more common unit on your test. In terms of frequency, you have Hertz(Hz).

Of course, if I were you, I'd take a quick search on Google just to be sure. After all, I'd feel bad if you failed your test due to prefixes.

But good luck Fred!

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