All Questions
Tagged with potential-energy homework-and-exercises
395
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My question is regarding gravitational potential [closed]
If you take a spherical shell, say of mass $M$, and then you split the shell in 2 portions by a plane other than the median plane....say that the larger portion is A and the smaller portion is B.......
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320
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Potential energy distribution near a cube with negative charges at 8 corners and one positive charge at its center
What is the potential energy of an arrangement of eight negative charges on the corners of a cube of side $b$, with a positive charge in the center of the cube? Suppose each negative charge
is an ...
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1
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Change in potential / potential energy of a charge in electric field [closed]
A uniform electric field of 2000 $(\frac V m)$ exists through all space (the field is in $+x$ direction). An electron is moved from the origin to the location where $x = -2.00 (m)$ and $y = +3.00 (m)$....
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Gravitational potential at the centre of Earth [duplicate]
Why does gravitational potential at the centre of the Earth is finite i.e. $V_c=\frac{3}{2} V_s$, as at the centre $r$ becomes zero so applying $V = \frac{GM}{r}$ the result must be infinity.
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Can kinetic and potential energy be converted to thermal energy? [closed]
If they can, can I use the potential energy equation to find out how much the temperature would increase if 1 kg of water is dropped to the ground from 10m height?
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The Theoretical Minimum: Lecture 5, Exercise 3. Finding equations of motion from potential energy [closed]
From Leonard Susskind's book The Theoretical Minimum.
"A particle in two dimensions, x and y, has mass m equal in both directions. It moves in a potential energy $V = \frac{k}{2(x^2+y^2)}$. Work ...
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Change in potential energy after infinitesimal variation in position
The a particle with the potential $V(x^2+y^2)$ undergoes an active transformation where
$x\rightarrow x+y\delta$
$y\rightarrow y-x\delta$
The exercise was to prove that the Lagrangian of the system ...
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Bertrand's theorem and nearly-circular motion in a Yukawa potential
The question has arisen as a result of working on part b of problem 3.19 in Goldstein's Classical Mechanics book.
A particle moves in a force field described by the Yukawa potential $$ V(r) = -\frac{...
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Force derived from Yukawa potential
This is with regards to problem 3.19 from Goldstein's Classical Mechanics,
A particle moves in a force field described by the Yukowa potential $$ V(r) = -\frac{k}{r} e^{-\frac{r}{a}},
$$ where $k$ ...
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Intuiting qualitatively the shapes of the eigenfunctions of a finite well-like potential, using the infinite well eigenfunctions as an inspiration
Consider, for example, the third excited state of an infinite square well:
Now consider the following potential:
If we wanted to sketch the rough shape of the third excited eigenfunction of this ...
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Derivation of balanced torque using conservation of energy [closed]
Let mass $m_1$ be placed at a distance of $x$ from the hinge such that the the plane makes an angle theta with horizontal
Then we drop $m_2$ at a particular distance $y$ from hinge such that after ...
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Feynman Lectures, Chapter 4, Fig 4-3
From the Feynman lectures Chapter 4, Fig 4-3
"We lifted the one-pound weight only three feet and we lowered W pounds by five feet. Therefore W=3/5 of a pound."
If there is a change of 3ft in ...
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1
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Gravitational potential energy between a black hole and a mass [closed]
Let's think that there is a black hole with mass $M$ and matter with mass $m$. Two objects have distance $R$. What is the gravitational potential energy between the black hole and the mass? How can I ...
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Radius of electron and electrostatic energy [closed]
The classical radius of electron is obtained from the electrostatic energy of a sphere of radius $r_e$ which is: $U=\displaystyle\frac{e^2}{4\pi \epsilon_0r_e}$. For the electrostatic energy of a ...
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Solving Particle in a Box using Newtonian Mechanics [closed]
so I'm trying to solve the one dimensional particle in a box problem known from quantum physics in a classical context. So according to Wikipedia (see picture on the right) we would get a particle ...
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The amount of work needed to dig a hole in the ground [closed]
I'm trying to calculate the amount of work that is needed to dig a hole in the ground (can be very deep) between the surface of the Earth with radius $R_{Earth}$ and some surface with radius $R$. As ...
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Question about principle of minimum total potential energy
So this question is really basic compared to some others on this website.
I was reading professor povey's perplexing problem, a book on physics problem solving. I came across a problem which is below....
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How to find the equilibrium point of a system that is bowl shaped and a mass inside the bowl with given potential energy function?
Question: $z=U(x, y)=ax^2+by^2, (a,b \in R^+)$ is the potential energy function of the system. How to find the equilibrium point of this system?
We have to find the equilibrium point of this system ...
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To Calculate Kinetic Energy of slippping chain overhanging over a smooth table as a function of length of overhang [closed]
Is it even possible to do so? (With only upto highschool level knowledge of mechanics ie without the use of things like Lagrangian mechanics if that is even useful here).
I know how the mass will be ...
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Trying to figure out the potential energy of a hanging rope [closed]
I was trying to figure out the potential energy of a hanging rope. The rope is hanging from a fixed support. The mass of the rope is $m$. And the length of the rope is $\ell$. The rope has a uniform ...
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How to solve Schroedinger's equation with Kratzer potential?
Kratzer potential is defined by
$$V(r)={\frac{\alpha}{r}+\frac{\beta}{r^2}}.$$
I read that the Schroedinger equation for this potential has an analytical solution in terms of hypergeometric ...
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What is the potential energy of the spring? [duplicate]
What is the potential energy of the spring?
On the left side there is a gravitational force $mg$ acts on the spring, same on for the right side. So, If force $mg$ streches the spring $x$ units then $...
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Problem involving gravitational potential energy [closed]
Two uniform solid spheres of equal radii $R$, but mass $M$ and $4M$ have a centre separation of $6R$. The two spheres are held fixed. A projectile of mass $m$ is projected from the surface of the ...
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Constrained relativistic particle under distance dependent force
I found this question while browsing for special relativity problems. There are no solutions and I am quite lost on how to proceed with it.
A relativistic particle of mass $m$ is bound to move along ...
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Electric energy from dipole moment
Conventionally one define electric energy as
$$
U = \frac{1}{2} \int \vec{E}(r') \cdot \vec{E}(r') d^3 x'
$$
where $\vec{E}$ is a Electric field.
And from textbook like Griffith, we know that ...
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Find the potential energy of this object when it is on the ground of the Earth [closed]
A mass $M=1kg$ has potential energy $U=0$ when the distance to the Earth is $\infty$. Find the potential energy of this object when It's on the ground of the Earth. (The potential energy of the object ...
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Derive gravitational potential energy for this system [closed]
This is on a study guide for my Physics 221 final. I feel like I almost got it but I am off by a sign error. Here is the question:
Here is what I got so far:
Known:
$$F_g = \frac{GMm}{r^2}$$
$$U_g =...
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Force along $x$ direction on a bumpy surface
Gravitational potential energy near earth is given by$$U(y)=mgy$$
Suppose a bumpy surface is described as $y=\sin(x)$, then $U$ varies with $x$:
$$U(x) = mg\sin x $$
Then the force along $x$ is given ...
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Understanding kinetic and potential energy
A bullet with mass $8g$ flying at the speed of $v_0=600$ $m/s$ strikes
an apple and comes out at the speed of $500$ $m/s$. Calculate the work
($A$) of the force exerted by the apple on the bullet.
...
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Work done by the electric field on the charge - Negative or Positive?
Below is a question from my physics textbook:
$X$ and $Y$ are two points in an electric field. The potentials at $X$ and $Y$ are $V_x$ and $V_y$ respectively where $V_x > V_y$. A small, positive ...
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#20 Science Work, 8th Grade [closed]
Problem:The potential energy of a 40-kg cannon ball is 14,000 Joules.How high was the cannon ball to have that much potential energy?
Please help me with this, I'm so confused '-'
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Velocity not affecting heat produced by impact
A bolt of mass 0.3 kg falls from the ceiling of an elevator moving down with an uniform speed of 7 $\text{m s}^{–1}$. It hits the floor of the elevator (length of the elevator = 3 m) and does not ...
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How much energy will be created using this method? [closed]
If I built a platform 100 meters high and put a crane on it then used solar power grid to drive the crane motor. Then using a 40 foot shipping container l filled it with dried sand. Then using the ...
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Why are there 6 interactions with 4 positive charges?
From a homework assignment, there are 4 spheres spaced 1cm apart. Each of the spheres are charged to +10nC and weigh 1 gram. The question wants us to find the final speed of the charges once they've ...
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simple work and kinetic energy problem (baseball)
problem says:
A baseball player throws a ball with a mass of $0.150kg$ with a speed of $40.0 m/s$ and an angle of $30$ degrees. What is the kinetic energy of the ball when it reaches the highest ...
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Is potential energy always inversely proportional to separation?
This is a question from Class 11 Physics NCERT.
The answer is that only graph (v) is correct and the reason given here is that potential energy varies inversely with separation. But does that always ...
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Simplified formula of potential energy giving different expected value of mass
I am trying to calculate the mass of a planet by the following image
I have the mass of the object, $2$ kg, and the radius of the planet, $5000$ km (also the gravitational constant $G$).
My first ...
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Energy change as ball rolls down a curved ramp [closed]
At the top of the ramp, the ball has gravitational potential energy. As the ball rolls down the ramp, the potential energy converts to kinetic energy. Due to friction, some energy is also converted to ...
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Work - Energy confusion when movement is vertical/up a slope
I've always thought of work done on an object as the energy transferred to it. This explanation, however broke down when I came across the following situation :
A block of mass $m$ is transported to a ...
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Work Done and Potential Energy in Electrostatics
This is a question from class 12 Physics NCERT Part 1:
I am having so much trouble with this, I can't figure out where I'm going wrong. I solved part (a) here:
(a) U= -27.2 eV
(b) Here, the kinetic ...
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From a potential energy equation, how can we determine whether or not the particle undergoes circular motion?
(I realise this may be considered a homework question but I have read the rules.)
I'm working through an introductory book on classical mechanics and there is this question:
Consider a particle of ...
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Potential energy of an object (with non-negligible size compared to distance from ground level)
Let's say I have a cylindrical water tank (with area $A$ and height $h$), and the bottom of the tank is $H$ meter from the ground.
So what is the potential energy of the water tank? If the $h$ is ...
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Change in kinetic energy of pendulum [closed]
"An object of mass m is tied to a string of length L and a variable horizontal force is applied on it which starts from rest and pulled slowly until the string makes an angle $\theta$ with the ...
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A pendulum consists of a rod with length L and a coin of mass m
A pendulum consists of a rod with length $L$ and a coin of mass $m$. The pendulum is held in a horizontal position and then is released with a minimum velocity needed to make a full circle.
What's the ...
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Change in potential energy of a parallel plate capacitor as a dielectric slab is moved in the space between plates
I was doing this question:
If a parallel plate capacitor made of square plates of side L and separation D is connected to voltage source V.
And then a dielectric slab of width D is introduced ...
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3
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The Lagrangian for gravitational potential energy in a double pendulum
For a double pendulum what would be the gravitational energy. I am trying to work out the Lagrangian for the double pendulum. I got the kinetic energy but I am struggling on the gravitational ...
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The work due to friction given an influential force
Statement: I am trying to work through Chapter 8, Problem #70 of OpenStax University Physics Volume 1 and I cannot figure out what I'm doing wrong. The problem statement is as follows:
A particle of ...
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Two different solutions for the expression of potential energy of a uniformly charged solid sphere [closed]
I am a bit confused because I did some rigorous derivation of potential energy of a uniformly charged solid sphere and got two different solutions.(Sorry for the long exercise)
Now have a look at my ...
user230246
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2
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Change in Energy when placing an object on the ground
It seems like a simple question but I was wondering where does the energy go when I place an object from a height on the floor.
Initially it's all stored as potential energy, and as I'm moving the ...
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353
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How Do I Calculate the Potential of System?
I was doing my homework when I came across this question:
Three equal point charges, each with charge $1.40 \, \rm\mu C$ , are placed at the vertices of an equilateral triangle whose sides are of ...
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