# Tagged Questions

Units are standards of measurement used for different types of quantities.

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### How can geometrized units have more than one constant equal to 1?

I can understand how you could manipulate units to make a certain constant equal to $1$, like $c$ or $G$, et cetera. But how can you make it so two constants (in this case $c$ and $G$) are equal to $1$...
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### About unit definition in numerical computation [closed]

I attend an undergraduate level course of quantum mechanics. I am thinking of computer computation on a quantum mechanical problem. I do not have much experience in numerical computation, so I read ...
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### Pressure at ground level and at sea level

1atm = 101325pa 1bar = 100000 pa 1atm = 1.013 bar 1bar = 0.987atm From wiki: The bar is a metric (but not SI) unit of pressure exactly equal to 100000 Pa.[1] It is about equal to the atmospheric ...
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### Why isn't $G=1$ as common as $c=\hbar=1$? [closed]

It is standard practice in theoretical physics to use a system of units in which $c=\hbar=1$. However, even though you could also set $G=1$, most physicists prefer not to. For example, in my cosmology ...
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### What is the purpose of taking coefficients as 1 in numerical solutions?

How can we recover the real solution after getting a solution by solving with parameters set to 1? For example, on my case to solve the Shrödinger equation via finite difference method, the author ...
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### Visualizing Physical Units in Phyiscs

I do best in physics when I can make sense of the units that accompany values, and I do this by visualizing in my mind what is happening. Take for instance, $v=\frac{s}{t}$. When I think of velocity I ...
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### Units of Fourier Transform [duplicate]

I am a bit confused about the units of continuous time Fourier transform. Let's say that $x(t)$ is an input signal and has units of volts. Taking the Fourier transform of this yields $X(f)$. I would ...
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### is Ù the same as omega as the unit of resistance?

I was making an exercise about DC motors and the resistance was given in Ù. Is this the same unit as Ω? Or is there a relation between these two units?
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### What in nature causes Newton's gravitation constant to have its given value?

Does the value of Newton's universal gravitational constant $G$ remain a mystery? Why does it have the value that it has?
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### Power statement is valid for MW Or KiloWatts? [closed]

If I can talk to someone and tell him that a new power plant inaugurated by Prime Minister will produce $60$ megawatts per hour, will it be true to use $\mathrm{MW}$ unit for Power?
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### Why are measurements standardized the way they are?

Using meters as a base length, squaring or cubing lengths smaller than 0.67m makes the square term larger than the cubed term. This fact causes certain properties of physics (how rain needs to form?) ...
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### Converting $W/m^2$ unit [duplicate]

In my equation I have a unit measured in MET found here $1MET=58.2 W/m^2$. But my other parameter which is metabolic heat generation is measured in $W/m^3$ . I want to convert $W/m^2$ units ...
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### Does unit linear scale lead to linear scale of time?

I'm modeling movement of charged particles on computer using Coulomb's law and Newton's motion laws. As I try to simulate motion of small particles on small distances with small charges, I use my own ...
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### Books or other sources for natural units, Planck units, dimensional analysis etc. for someone with only high-school physics knowledge

I'd like to know more about natural units, Planck units, dimensional analysis, etc., and things like how units are "created" by man or by the universe, universal constants and where they come from. ...
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### Educational benefit of putting units outside of variables? [closed]

When I studied physics (both in high-school and university), in all of the worked examples, variables would be used to denote physical quantities, and thus include dimensional units. For example, ...
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### How do Hubble Units work?

I'm reading through a document - Briel et al (1992) (pdf) - and I've come across Hubble units with which I'm not familiar. How do you interpret something like $$h^{1/2}_{50} \:\mathrm{cm}^{-3}$$ or ...
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### Units of Velocity Components and Metric Tensor Components

I was watching a GR lecture on youtube, and the speaker explains that the units of the components of velocity are $[v^{\alpha}]=\frac{1}{T}$, the metric tensor has units $[g_{\alpha\beta}]=L^2$, and ...
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### Definition of unit of force [closed]

As we know $1\ \mathrm{N}$ is the force which can accelerate $1\ \mathrm{kg}$ mass with $1\ \mathrm{m/s^2}$ acceleration. But for which surface is this definition given? I mean a $1\ \mathrm{kg}$ ...
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### cm^-1 and ns^-1 relationship

In my last Phys.SE question Emilio Pisanty mentioned this relationship $1 cm^{-1} = 10^n c^{-1} ns^{-1}$. I was wondering where this relationship came from. Does anybody know? Second of all, I am not ...
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### How to compare dimension of this with velocity [closed]

Prove that the dimensions of $\large \sqrt{\frac{1}{με}}$ are that of the velocity?
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### System of Units where Coulomb's constant $k_e = 1$?

I am reading (and trying to replicate the results of) a paper in the field of condensed matter physics. The system consists of a spatially separated electron and hole whose Coulomb interaction is the ...
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### Why does physical quantity misinterpretation result in near-identical torque results?

I am going to use an equation $$\text{torque} = \frac{\text{power}\times 5252}{\text{RPM}}$$ derived on Wikipedia. Suppose that $\text{power} = 100\ \mathrm{hp}$ and $\text{RPM} = 5252\ \mathrm{rpm}$ ...
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### How the standard units for length force and time are defined in US Customary Units as standard units are defined in SI?

I'm much confused about US customary units so I want to ask a lot more questions under single question.First how standard units ,in US customary Units,of force time and length are defined as second or ...
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### Units of the derivative of a function

I have a function $\phi(\mu, \sigma)$. $\mu$ and $\sigma$ are voltages (in mV in my case), so $\phi$ is a function of two voltages. $\phi$ itself, however, is in units of time (ms in my case). (...
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### How do I convert pressure and flow from Imperial to metric units?

I'm not a physicist or have much experience in engineering. However, for a programming task, I need to change code that calculates "pressure, head, feet of fluid, gauge" into "meters of head, absolute"...
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### What defines a unit system and how many constants can we set to 1?

Is it possible to have a system of units in which both $\frac{1}{4\pi\epsilon_0}$ and $c$ equal 1?
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### What happens to the units when squaring a variable?

What happens to the units of a squared variable? For example, if I squared velocity, would the units, metres per second (${\rm m}/{\rm s}$), change as well?