# Tagged Questions

A set of numbers used to quantify location in space.

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### Conformal transformation/ Weyl scaling are they two different things? Confused!

I see that the weyl transformation is $g_{ab} \to \Omega(x)g_{ab}$ under which Ricci scalar is not invariant. I am a bit puzzled when conformal transformation is defined as those coordinate ...
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### Velocities from rotating frame of reference to fixed frame of reference [on hold]

I have the following flexible structure, where P1 coordinate system is fixed to the ground and P3 is rotating around the $y_3$ axes. I would like to model this structure as a simple steady state ...
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### Why do we use orthogonal axes?

I have been asked several times that “why do we use orthogonal axes in coordinate systems?” and I was always replying that “because of simplicity”. But, today morning, someone asked me that question ...
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### Momentum flux through cylinder wall

A fluid flows through a hovercraft, is bended and the freejet has a certain velocity $c$ with which it flows after exiting the hovercraft / beeing bended. There's a pressure difference between under ...
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### Notations used to express direction [closed]

We express direction relative to a reference point and call a certain direction positive and it's direct opposite direction negative, by convention. But, what notation should we use to express a ...
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### Locally remove a gravitational field

Let $K$ be an inertial frame of reference on $\mathbb{R}^3$ and $g=g(t,x)$ a nonuniform and nonstatic gravitational field. How I can choose a system of reference $\bar K$ such that mechanical effects ...
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