Questions tagged [dimensional-analysis]

Dimensional analysis means to obtain results by analyzing the units in question, etc. DO NOT USE THIS TAG if your question is about degrees of freedom or spatial dimensions.

668 questions
Filter by
Sorted by
Tagged with
1answer
58 views

Bohr's atoms model

Why might Bohr have been especially curious about the possible values of the angular momenta of electrons in quantum mechanics? What looks special about them?
1answer
80 views

Unit vector in displacement

When we use vectors in physics why does the unit vector (for displacement) equals magnitude of 1 or magnitude of 1m?
2answers
102 views

1answer
55 views

Possible fundamental dimensions in Pi Buckingham theorem

While the Pi Buckingham is often taught in a fluid dynamics context, in which the relevant fundamental dimensions are generally : Mass, Length, Time and Temperature, it can obviously be applied to ...
1answer
181 views

Non-dimensionalization of Navier-Stokes equations multiphase flows

I am currently dealing with multiphase flows and have to use the non-dimensional form of the Navier-Stokes equations (NSE). In the scientific literature I found various formulations (and almost no ...
3answers
156 views

Whats the dimension of no of molecules per unit volume

I know its trivial but still i am confused,i know that no of molecules per unit volume (n) is dimentionless but my confusion is what if we describe it by total number of molecules by total volume(n=N/...
0answers
77 views

Non-spreading wave packets

I am reading an article (Nonspreading wave packets, by Michael Berry, Am. J. Phys. 47, 264 (1979), author eprint), and I have some questions about the maths within. First of all they take a wave ...
2answers
1k views

0answers
33 views

In non-dimensionalization, what does it mean when one “assumes” a quantity has been scaled relative to another quantity?

I'm trying to replicate the results of a paper, and they use the quantity $l$ to denote the length of the recirculation zone behind a cylinder for a problem regarding fluid flow past a cylinder. Early ...
3answers
6k views

What is the unit for work done?

My textbook's equation for work done is: work done = force * distance So this means that the unit should be Nm. However, when I researched on Google, a lot of people were saying that the unit is J....