The linear-systems tag has no wiki summary.
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2answers
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Undamped oscillations. Why is the solution a linear combination of $\sin()$ and $\cos()$?
$ma = mg - cx$, where $x(0) = x_0 = 0$ is the position in which there is no tension in the rope. $dx/dt = v_0$ for $t = 0$; $v_0$ is a known constant.
The discriminant of the characteristic ...
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0answers
61 views
Small oscillations [closed]
I am asked to consider a fixed homogeneous rod of length $2L$ and mass density $\rho$ It is centered around $O$. A particle with mass M is moving in the same plane. The attractive force between the ...
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0answers
61 views
linear response for a simple harmonic oscillator
Really sorry for this simple question, but I think it will be useful/interesting in general.
Consider a quantum simple harmonic oscillator.
Add a perturbation $H_I = -\lambda \hat{x}$
Calculate ...
2
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3answers
62 views
Solving systems of equations in dynamics
I have an exam in two days for first year university physics. Often for dynamics problems, I am required to solve algebraic systems of equations by hand, and this can be very daunting.
When I see ...
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0answers
204 views
What is the Laughlin argument?
The fundamental question is
Why is Hall conductance quantized?
Let's start with the Hall bar, a 2D metal bar subject to a strong perpendicular magnetic field $B_0$. Let current $I$ flow in the ...
3
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2answers
116 views
Many faces of linear response theory
I have seen two forms of linear response:
One is in the calculation of susceptibilities using Green functions.
The other is in the evaluation of response currents, say, London current of a ...
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4answers
400 views
What does superposition mean in quantum mechanics?
What does superposition mean in quantum mechanics?
When I say $A+B=C$ (forces). I can mean push something with force $A$ + force $B$ together, and that is same as I push it with force $C$.
But when ...
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1answer
107 views
Microphones, Loudspeaker and their analogies to spring mass system
I have just started studying Microphones and Loudspeakers. I need a good text to refer which can explain their mechanical analogies with simplicity and basics too.
2
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1answer
276 views
Is the universe linear? If so, why?
Simple question, I'm trying to build a quantum memory system that utilizes the superposition principle to model specific phenomenon I am trying to predict, anyways, my question is this.
Is the ...
-1
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1answer
202 views
Hit a moving target [closed]
There is an object moving from $(X_1,Y_1)$ to $(X_2,Y_2)$ with speed of $V$. there is a third object in in $(X_3,Y_3)$.
now I want to hit the first object with the second one. and imagine that the ...
7
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4answers
705 views
Why is the Principle of Superposition true in EM? Does it hold more generally?
In the theory of electromagnetism (EM), why is the principle of superposition true? Can we read it off from Maxwell's equations directly?
Does it have any limit of applicability or is it a ...
0
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1answer
65 views
energy field, sum of charges [closed]
Let's say I have a linear field with one "point source" of "power" $B$. At a certain distance, I have $A = \frac{B}{d^2}$.
Now I have a grid of size $X \times Y$, with $N$ sources at random ...
9
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1answer
773 views
Matrix solution of an equivalent resistance circuit problem
Start with a set of points $x_1, x_2, \ldots$ that are connected by wires with some resistance. Represent the resistance by a conductance matrix (conductance being one over the resistance), where ...
8
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1answer
235 views
Can the Kramers–Kronig relation be used to correct transfer function measurements?
In experimental physics, we often make measurements of linear transfer functions; these are complex-valued functions of frequency. If the underlying system is causal, then the transfer function must ...
