All Questions
Tagged with potential-energy homework-and-exercises
395
questions
4
votes
2
answers
338
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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 ...
- 1,088
0
votes
1
answer
60
views
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 $...
- 699
1
vote
2
answers
79
views
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 ...
0
votes
1
answer
83
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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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1
vote
1
answer
310
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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 ...
- 3,622
0
votes
1
answer
142
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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 ...
- 699
-1
votes
3
answers
1k
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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:
$$F_g = \frac{GMm}{r^2}$$
$$U_g =...
- 101
1
vote
1
answer
60
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Force along $x$ direction on a bumpy surface
Gravitational potential energy near earth is given by$$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 ...
- 908
1
vote
2
answers
132
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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.
...
- 149
2
votes
2
answers
2k
views
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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-1
votes
1
answer
101
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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 '-'
1
vote
3
answers
136
views
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 ...
- 147
0
votes
1
answer
33
views
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 ...
- 1
1
vote
2
answers
60
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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 ...
- 155
1
vote
2
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261
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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 ...
- 11
1
vote
1
answer
1k
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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 ...
- 83
0
votes
2
answers
51
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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 ...
- 105
0
votes
2
answers
3k
views
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 ...
- 33
2
votes
3
answers
4k
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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 ...
- 163
1
vote
1
answer
238
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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 ...
- 83
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votes
0
answers
50
views
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 ...
0
votes
1
answer
45
views
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 ...
- 2,566
-1
votes
1
answer
178
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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 ...
- 169
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vote
0
answers
77
views
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 ...
- 11
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1
answer
970
views
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 ...
- 243
0
votes
3
answers
505
views
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 ...
- 119
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votes
1
answer
61
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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 ...
- 103
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votes
1
answer
876
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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
2
votes
2
answers
1k
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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 ...
- 131
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2
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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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