# Questions tagged [physics]

Questions on the mathematics required to solve problems in physics. For questions from the field of mathematical physics use (mathematical-physics) tag instead.

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### Correct Setup of Coupled and Hierarchical Harmonic Oscillators

I am interested into understanding the behaviors of weakly coupled ascillators. Several books I have looked into give some really good insights and I wanted to look into a specific idea I had a bit ...
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### Determining functional form of depth-dependent index of refraction, given transit time as a function of depth

A pair of radio receivers at known, fixed locations are placed atop a medium whose index of refraction varies as a function of depth. We may assume that this index of refraction has a known functional ...
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### Need help in quantitatively modeling solubility of carbon dioxide in beer.

I'm trying to model a 3D surface which reflects the solubility of $CO_2$ in beer. An empirically derived chart is available at this link. Solubility is empirically related to the pressure of $CO_2$ in ...
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### Deriving from Doppler's formula

I am studying Doppler sonography. I do understand doppler's formula: $$f=f_{0}\frac{v}{v-u},$$ where $f_{0}$ is emitted frequency, f is received frequency, v is speed of the ultrasound puls and u is ...
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### How to solve this question? I tried changing velocity to m/s and also tried changing acceleration to km/h^2 but i cannot get the answer still.

A car is travelling at a velocity of $60km/h$. It then accelerates at $200m/s^2$ for $2$ min. Calculate its final velocity? (Answer: 84km/h)
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### Cosine Integral (Lattice-discretized Laplace Equation in 2d)

$\newcommand{\rr}{\mathbf{r}}\newcommand{\ee}{\mathbf{e}}\newcommand{\qq}{\mathbf{q}}$ Hello community, I have been working on a sum for a bit. The idea is to derive a fundamental solution (Green's ...
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### Oblique collisions question, how can coefficient of restitution be negative?

question: https://imgur.com/EfH4p8J, solution: https://imgur.com/PdZKk8A  As you collide with the wall, you will have a velocity before and after. So a formula the answer uses, where e is the ...
1 vote
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### How to calculate spectrum of a $3$-dimensional scalar field? [closed]

I have a data of three-dimensional turbulent scalar field $s(x,y,z)$ with $(x,y,z)\in [-3,3]\times [-3,3]\times [-6,6]$. The values of the scalar field are known and distributed on the regular grid ...
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### Show exterior derivative is equal to this wedge product: $d F_5 = H_3\wedge F_3$

I have to show $d F_5 = H_3\wedge F_3$. This is one of the Bianchi identities for a solution of type IIB supergravity equation of motion, though I think that my problems are more mathematical than ...
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### Uniform Horizontal circular motion of a car on a banked slope with friction.

I came up with this question, to try to help my understanding with uniform circular motion of an object on a banked slope: A car moving with speed $144$kmh$^{-1}$ is on a banked inward slope, the ...
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### Can a 4D spacecraft, with just a single rigid thruster, achieve any rotational velocity?

It seems preposterous at first glance. I just want to be sure. Even in 3D the behaviour of rotating objects can be surprising (see the Dzhanibekov effect); in 4D it could be more surprising. A 2D or ...
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### the deviation of the string from the equilibrium state is given by the function

I tried laplace but didn´t work. i don´t know how to start it
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### What are the conditions for two vectors to be equal?

I am going through a derivation of a physics theorem (particulars are not important). It involves a sphere centered at the origin. The observation is made that $\hat{n} = \hat{r}$ (unit normal to ...
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### Period of Cartan 3-form

A Cartan 3-form in a Lie group $G$ is defined as: $$\omega = Tr(g^{-1}dg\wedge g^{-1}dg\wedge g^{-1}dg)$$ For $g$ being maps $g:B\longrightarrow G$, with $B$ a given manifold. The so-called periods of ...
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### OCR Further maths A Level Mechanics Exercise 4B Q 9: Question on circular motion

Two particles $A$ and $B$ of mass $40$g and $30$g respectively are attached to opposite ends of a light inextensible string of length $30$cm. Particle $A$ rests on a rough horizontal spinning table ...
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### Dealing with second derivatives in error calculation

I need to find the relative error in the error of $\log P$, i.e. $\frac{\Delta(\Delta \log P)}{(\Delta \log P)}$. I need to prove that this equals $2\frac{\Delta P}{P\log P}$. I have tried so many ...
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### Finding Acceleration of gravity and radius of a planet through a pendulum

A simple pendulum has a period of P on Earth. When taken to another planet of same mass, P decreases by 13%. What is the acceleration of gravity and the radius of the unknown planet?
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### Position compensation after rotation

I am working in a game. I have a spaceship which can accelerate in any direction and can rotate around any axis (in 3D space). I want to have all other bodies in the world remain in exactly the same ...
1 vote
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### How to represent this one-dimentional movement in math?

I'm struggling trying to convert this movement behavior into an equation. For future reference, this is as a result of searching for a solution for a previous question of mine. Thank you @eyeballfrog ...
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### How do I calculate the gravitational force that a line-segment of uniform mass exerts on a point in 3D space?

For my purposes: The point can be assumed to always have a mass of 1. The mass of the line is uniform, and directly proportional to its length. Here is what I have so far: Let the line start at ...
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### Constrained smooth transition between points.

Since I'm not very skilled at math, I'll try to explain my problem with apples. At a certain train station, every train driver has a specific route to cover everyday. A pair of brothers, who happen to ...
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### Vector valued definite volume integral

In the context of a seminar lecture on some physico-chemical subject (magnetic shielding by electrons on atomic scale) I wanted to present a simple analytical example for the solution of an equation ...