Questions tagged [homework-and-exercises]
Applies to questions of primarily educational value - not only questions that arise from actual homework assignments, but any question where it is preferable to guide the asker to the answer rather than giving it away outright. Please READ THE GUIDANCE IN META before asking homework-like questions.
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Problem explanation from Estonian-Finish Physics 2003 olympiad [closed]
I am having trouble understanding problem 5.3 (Vibrations) from the Estonian-Finish 2003 Physics olympiad. Specifically in 5.3 they say "brick is kept in motion along(horizontal) $y$-axis by a ...
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Could you please answer my questions (I have four questions)? [closed]
1.must the positive direction is always upwards when we study systems that have springs in a vertical way and we cannot assume that the positive direction is downwards?
If I understand correctly, how ...
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Minimum energy to be given to a swing for it to completely coil up around the main support bar [closed]
The question is the title. To find the minimum energy to be given to a swing for it to completely coil up around the main support bar.
Generalization, swing can be thought of as a single pendulum. By ...
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A question on modified flux function under perturbation [closed]
Given a magnetic field $\mathbf{B}=B_{0}\left(\dfrac{xz}{z_{s}^{2}},\dfrac{yz}{z_{s}^{2}}, 1-2\left( \dfrac{x^{2}}{r_{s}^{2}}+\dfrac{y^{2}}{r_{s}^{2}}\right) -\dfrac{z^{2}}{z_{s}^{2}}\right)$ with the ...
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Electrostatic potential outside of a charged ball [closed]
To preface, I have never solved Maxwell's equation or his resulting Poisson's equation in any coordinate scheme, nor am I a physics major. I'm entirely teaching myself how to do this, so I don't know ...
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How does the moment of inertia work in this physics question? (Vibrations and Waves by George C. King) [closed]
Not sure if this is just me having a moment where I'm missing something totally obvious, but I'm going over some old undergraduate physics work to reinforce my knowledge, and I've encountered a step ...
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Centrifugal Governor Question [closed]
I've been working through Hand and Finch's Analytical Mechanics and have just attempted this question:
My attempt at a solution is as follows:
First, find the kinetic energy of the two masses $m$ by ...
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Mahan's derivation of energy current of a free-particle system
On p.25 of the 3rd Ed. analogously to the polarisation operator $\textbf{P}$ for particle currents
$$\textbf{P}=\int\textbf{r}\rho(\textbf{r})d^3r$$
he defines an operator
$$\textbf{R}_E=\frac{1}{2}\...
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Find curve minimizing energy loss due to friction [closed]
I am looking for an ansatz of the following problem:
Given a mass $m$ moving in a constant gravitational field along curves $C$ connecting two fixed points I want to find the curve $C_0$ that ...
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What is this bar for? [closed]
There is a bar in front of the classroom’s blackboard. I wonder what it is for? It shouldn’t be for people to stand on it as then it should be a plank instead of a tube.
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How does an object with friction fly off of a disc with angular acceleration? [closed]
Consider the image below
An object is resting on a rotating disc with angular velocity w and it is at rest with respect to the disc. Now if we increase the angular velocity of the disc(give it an ...
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What are the operators here and how are these formulas derived? [closed]
In (23), are grad and div some kind of scalar operators comparing to $\nabla$ and $\nabla\times$? because tbh I dont know how $\text{curl}(\mu^{-1}\text{curl}\textbf{A})$ turns into $\text{div}\mu^{-1}...
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A level physics particle and radiation question [closed]
i am currently self-teaching a level physics through youtube vids, cgp book, and the hodder education book and I am currently struggling with these two questions
For question 23 the model solutions ...
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How can i find the amount of charge that "escaped" to ground in this conductors and capacitance question? [closed]
In the image, you have a plate capacitor, and in the space between its plate, a metallic material with charge $+Q$ is inserted.
the question asks how much charge will pass through each wire between ...
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Volleyball Question [closed]
I apologize in advance... I know nothing about physics. I'm setting up an indoor volleyball practice area for my 11 y/o daughter to practice her serves. When serving, the normal distance to the net is ...
