English units are the units of measurement used in England up to 1826 (when they were replaced by Imperial units), which evolved as a combination of the Anglo-Saxon and Roman systems of units. Various standards have applied to English units at different times, in different places, and for different applications.
The two main sets of English units were the Winchester Units, used from 1495 to 1587, as affirmed by King Henry VII, and the Exchequer Standards, in use from 1588 to 1825, as defined by Queen Elizabeth I.The English units were replaced by Imperial Units in 1824 (effective 1 January 1826) by a Weights and Measures Act, which retained many though not all of the unit names and redefined (standardised) many of the definitions.
Use of the term "English units" can be ambiguous, as, in addition to the meaning used in this article, it is sometimes used to refer to United States customary units, which have somewhat different definitions, or to Imperial units, the standard units throughout the British Empire and Commonwealth.
The original quantity is given in this paper: [reference][1], equations: (31-33-34), where ##a(\eta)= \frac{1}{H\eta}##, so I considered in (1) only the constants which share by dimensions to ##P##.
Any help is appreciated!
[1]: https://arxiv.org/pdf/hep-th/0703290
Sorry if there are mistakes regarding the post itself, this is my first time posting.
This an easy problem to solve, but this isn't what I'm looking for, but first of all, you can plug in the values and solve for ##\omega##, and it equals ##\frac{170 V}{0.87 T(0.0300 m^2)}## = 6513 Hz, my...
Hello everyone,
I am curious, suppose you have a function ##f(x)=x^3## and you to find the area under the curve from 0 to x, the area would be ##\frac {x^4}{4}## but this is units of ##L^4## if x is length, but area is units of ##L^2## so what is going on here?
The reason I'm curious is I...
I stumbled over a datasheet of an old pentode where it says, in the english translation:
I thought, wow, I am not sure if I wouldn't have written Ug3=0V instead. I am a theoretician in physics but work more as an engineer and teacher.
What happens inside of me seems to be the following:
The...
Hi all,
I've struggled to resolve a units issue in this 1973 paper by Hora:
https://www.academia.edu/23774741/Estimates_for_the_efficient_production_of_antihydrogen_by_lasers_of_very_high_intensities
From the paper:
"
The number N_p of pairs produced in a plasma volume V during a time \tau and...
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https://www.yahoo.com/news/waste-time-community-college-transfers-043010995.html("Other" picked because not sure this...
Quick and possibly stupid question, but in the equation for calculating the electric field:
##{\mathbf E} = \frac{1}{4πe_0}\frac{q}{r^2} \hat {\mathbf r}##
What unit is ##q## in? Coulombs?
Although now that I think more on it I suppose it also depends on the units you're using to calculate the...
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As I understand it, when the squeezing operator acts on an annihilation/creation operator, a function of sinh(r) and cosh(r) is produced, where r is the squeezing parameter. I've been reading some papers that say that up to '15 dB of squeezing' have been produced in a laboratory. Does this mean...
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Hello, I was in class and came up with the question of: is there any physics formula in which a number with units is part of the exponent of said formula, and if there is how do the units behave?
Such as for example (x meters)^(y seconds)
Thank you in advance.
I'm looking for an undergraduate-level 'mathematical methods' or 'engineering mathematics' book that uses SI units for the purpose of self-study.
I've had my eyes on Zill's Advanced Engineering Mathematics, but it seems to use US customary units. So ideally I'm looking for a book that covers...
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After all, there is a square root in their expressions.
And the value of the Planck mass is 20 orders of magnitude greater than the average values of elementary particles.
$$ m_{pl}=\sqrt{\frac{1}{2\pi}\cdot \frac{hc}{G}}$$
The order of the value of...
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I wanted to find the number of protons striking a surface area during a solar event and the units provided are: #/(cm^2 s sr). Say I have a 1 m^2 surface area directly facing the sun, how do I use those units to discover the number of protons/s. What is the value of the solid angle to...
Proof:
Let ## a ## be any integer.
Applying the Fermat's theorem produces:
## a^{2}\equiv a\pmod {2}, a^{5}\equiv a\pmod {5} ##.
Observe that
\begin{align*}
&a^{4}\equiv a^{2}\pmod {2}\equiv a\pmod {2}\\
&a^{5}\equiv a^{2}\pmod {2}\equiv a\pmod {2}.\\
\end{align*}
This means ## a^{5}\equiv...
I didn't remember the Lavoisier died at the guillotine.
The world's roundest object helps solve the longest running problem in measurement -- how to define the kilogram. I knew about the Pt the Pt-Ir standard. I didn't realize that the mass of various 'standards' changed in time...
Velocity as a function of time, defined with units attached (Quantity feature of Mathematica):
fnVq[t_ ]:= 2 m/s^2 * t
fnVq[5 s]
Integrate[fnVq[tt],{tt,0 s, 2000 ms}]
10m/s
4m
When we printed above the value and integral, we got the correct results with proper units.
Now I'm trying to...
suppose you write, clockwise, n numbers (or "units", doesn't matter) in a circle. you then color, clockwise, each k-th number. you do this until you've colored all n numbers, or until you've reached an already colored number. let x be the number of colored numbers.
i've figured that if...
I was reading this paper, and I got confused:
https://projecteuclid.org/journals/communications-in-mathematical-physics/volume-31/issue-2/The-four-laws-of-black-hole-mechanics/cmp/1103858973.pdf
It discusses the Kerr solution for the case of { M4 > J2 } where M is mass & J is angular momentum...
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0.023901488
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Summary: The transition rate matrix for a problem where there are 5 Processing Units
A computer has five processing units (PU’s). The lifetimes of the PU’s are independent and have the Exp(µ) law. When a PU fails, the computer tries to reconfigure itself to work with the remaining PU’s. This...
How to transform density unit in natural units $MeV^4$ to SI units $kg/m^3$,
Here's my trial:
##MeV^4 = (10^6)^4 ~ eV^4 = 10^{24} ~ eV^4 ##,
## eV = 1.6 * 10^{-19}~ kg~ m^2 / sec^2, ##
##MeV^4 = 10^{24} ~ 1.6^4 * 10^{-40} ~ kg^4 m^8 / sec^8 ##
This is not simply ##kg/m^3##!
Any help how to...
Im trying to us 1.6*10^7 N/cm^2. this breaks to (kg*m/s^2)/cm^2. I need my units in terms of cm. So can I convert 1.6*10^7 kgm/s^2/cm^2 to
1.6*10^11 (kgm/s^2)/(m^2) then reduce to 1.6*10^11 kg/ms^2. The go back to cm and have 1.67*10^9kg/cms^2
In natural units, it’s known that the unit of the cosmological constant is ##eV^2##.
I don‘t get why in this paper :
https://arxiv.org/pdf/2201.09016.pdf
page (1), it says the value of ##\Lambda \sim meV^4##, this means ##\Lambda \sim (10^6 ~ eV)^4 \sim 10^{24} eV^4 ##, shoud not the unit ##eV...
so I have never seen this unit before. 10^-6m/mK for the thermal expansion (linear expansion). I believe this unit is micrometers divided by mili kelvins?
Fundamental units are defined as - each of a set of unrelated units of measurement, which are arbitrarily defined and from which other units are derived.
while Supplementary units are - Supplementary units are the dimensionless units that are used along with the base units to form derived units...
I'm trying to calculate the electrostatic energy, and I'm wondering what happens when I dot the D-field and E-field, with Si-units V/m**2. This is my equation:
D dot E = (-4x(epsilon) V/m**2)(-4x V/m**2) + (-12y(epsilon) V/m**2)(-12y V/m**2)
Are the final Si-unit still V/m**2 or V**2/m**4?
Would anyone know of a book or article that comprehensively explains Natural Units? I am looking for a document that explains all the versions of natural units and why, when, and how to use these units. I am looking for a source that provides many examples of how to use Natural Units. I found...
Hello Gentlemen,
I'm not an EE engineer, yet trying to help my colleagues. I would like to get a general feeling of what could be going on.
Probably trivial for some of you.
Background
We have a motor/torque sensor device that is measuring torque values. We get out digital signals for Torque...
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Hello everyone,
I'm sorry if this is not the right sub-forum to post this, but this doubt has been haunting me for a while.
I've got some rotatory machine -let's say, generic synchronous machine-. Turns out there are typical values for [kg m^2] (inertia) in the 2-10 range; the software I'm...
In fact, the only programming language I know of that implements something like units is the programming language Frink.
In other programming languages, the implementation is left to the programmer, for example C++ can implement this as a class.
We all know that a flowing fluid acquires dynamic pressure as a result of this velocity. But the pressure has been known to be the kinetic energy of unit volume of flow i.e. 0.5 times density multiplied by the square of the velocity. I just want to know how to convert that into units that are...
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Ok, so basically my task is to calculate the apparent diffusion D based on experimental data, which is kind of easy, BUT the problem is with unit of b...
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Delta is the pulse...
I'm trying to solve for this in a deuteron problem. But can't seem to get the right answer.
The reduced mass of the deuteron is 469.4 MeV, the binding energy Eb is 2.226 MeV and R = 1.5fm.
Using hbar = 6.5817x10^-16 eV.s
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I could not find any clear explanation on multiplying quantities with different units while including their uncertainties. For example, how would you compute the following product with their uncertainties? 3.4 Newtons +/- .12 Newtons x 1.7 seconds +/- .23 seconds
I do not understand how in part a, the units for K can be N/m. If Work is in joules which is kg*m^2/s^2 and we are diving by x^2 which is m^2, then m^2 should cancel out and we should be left with kg/s^2.
Kg/s^2 makes more sense because in part b when you find the work done you are multiplying...