How to Choose Prefix for Physics Exam

  • Thread starter Thread starter SwedishFred
  • Start date Start date
AI Thread Summary
Choosing the correct prefixes for physics exams on waves and energy is crucial. Energy is typically measured in Joules, with variations like kiloJoules, milliJoules, and microJoules commonly encountered. For wave-related questions, wavelength is often expressed in meters or nanometers, while frequency is measured in Hertz. It's advisable to verify these units through additional research to ensure accuracy. Understanding these prefixes can significantly impact exam performance.
SwedishFred
Messages
28
Reaction score
0
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
 
Physics news on Phys.org
The right prefix for what? Your question is not clear.
 
Herr Doktor Professor always works for me as a Prefix.
 
SteamKing said:
Herr Doktor Professor always works for me as a Prefix.
:smile:
 
SwedishFred said:
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

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!
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top