1. ### I Angular momentum and spin unit

I know that spin is a type of intrinsic angular momentum. For electron spin is (1/2)ħ . But unit of (1/2)ħ is J.s, which is not the unit of angular momentum. Can you please explain this discrepancy?
2. ### B Equilibrium - Scalar or Vector?

1 Is Equilibrium a Scalar or Vector quantity? 2 What is the unit of Equilibrium? Thanks & Regards, Prashant S Akerkar
3. ### B The fundamental units in Physics

I have been in my physics crash course for my entrance exam. I was looking at the chapter "Units and Measurement". I got a doubt in this chapter and I didn't get it cleared by my teacher. So I am posting this in this forum. We have 7 fundamental quantities and other quantities are derived...
4. ### B Why I think radians should *not* be dimensionless

As most know and rest can find out, radians are a dimensionless unit. Actually, it's even worse: angle in general is a dimensionless quantity. That stems from it being defined as a ratio of the arc versus the radius. I now present my opinion of disagreement to this concept. In the strict...
5. ### I Is it possible to calculate Tsupercon from the unit cell?

Hi folks, It is an elementary question for people expert in superconductivity. I know there is a theory, the BCS theory, and the GIzburg Landau theory too that apparently explains superconductivity. My question is, if I give you a unit cell would you be able to tell me the temperature at...
6. ### What unit symbol is this

what does "Gg" represent ?
7. ### Measuring volume: Solid vs Liquid/Gas

I was just curious... what is the practical reason behind having two separate units for measuring volume? For instance, we can use cubic centimeters and mL interchangeably in practical medicine, i.e. injections. But we tend to use cubic (centi)meters for solids, and liters for liquids/gasses...
8. ### B Entropy and Hawking radiation

Dear PF Forum, I'm trying to make sense about Hawking radiation in Black Hole. And that leads me into entropy. I read this equation in https://en.wikipedia.org/wiki/Entropy What does that mean? S is the change of Entropy What does Qrev mean there? Is it in Calorie? then Joule? T, I think is in...
9. ### 3 phase power systems: per unit with transformers

Hey, I'm currently working a problem that looks like this: There's more to this problem, but I'm sure I can solve the rest of it, there are just things I'm uncertain about. Actually, it's only one thing I'm uncertain about. I'm looking through my notes, and when converting the voltage...
10. ### Unit of acceleration

Dear PF Forum, I have a problem concerning the unit of acceleration. All this time in Relativity, we have been talking about c. Either as a distance unit (light travel for 1 second) or as speed. Sometimes we describe it as 300,000. Sometimes as 300,000,000 or 186,000. The time unit is always...
11. ### Rate of acceleration

if acceleration is defined as rate of change in velocity, then how do you find out the unit of rate of change of acceleration?
12. ### Radians and the unit of rotational energy

Hello everyone I have a question regarding radians and the unit of rotational energy (which has been probably asked several times elsewhere but is still confusing for me :-) ). As I understand radian (rad) is a UNIT that is dimensionless (thus cannot be omitted), correct ? Now if I want to...
13. ### Universal? or Multiple Units of Measure?

Firstly, I'd be happy to be corrected if I'm not using the right wording or just plain incorrect with my approach. Is it practical to suggest that units of one measurement system could possibly represent the measurement of things not only at the macro level, but represent particles with and...
14. ### Direction of the maximum gradient (scalar fields)

If a question asks for the direction of the maximum gradient of a scalar field, is it acceptable to just use del(x) as the answer or is the question asking for a unit vector? Thanks