All Questions
26
questions
0
votes
3
answers
196
views
I know that electric potential energy is defined for a system of charges, not for a single charge. But what about electric potential?
My professor explained me in the best manner possible about the electric potential energy and why it is NOT defined for a single charge, BUT my question is as Electric potential is just electric ...
- 23
0
votes
1
answer
24
views
Restriction to a region of potential energy [closed]
A particle with total energy E is moving in a potential energy region U(x). Motion of the particle is restricted to the region when?
(A) U(x) > E.
(B) U(x) < E.
(C) U(x) = 0.
(D) U(x) ≤ E.
I ...
0
votes
1
answer
97
views
Lorentz force from potential- extra term?
I'm trying to verify the E.M potential energy $U= \int{A_\mu J^\mu} = q(\phi - A_j v^j )$ by using the connection:
$$
F= - \frac{\partial U}{\partial r} + \frac{d}{dt} \frac{\partial U}{\partial v}
$$...
- 2,141
0
votes
2
answers
239
views
Direct calculation of the gravitational potential inside a hollow sphere
I calculated the gravitational potential inside a massive sphere with constant density and got the result:
$$\Phi = -2\pi G\rho R^2 + \frac{2}{3}\pi G\rho R_p^2$$
Where $R$ is the radius of the sphere ...
- 16.7k
0
votes
1
answer
213
views
Electric Potential, Work, Potential Energy, and Electric Field [closed]
I don't quite understand these concepts. What is the relationship of electric potential with work, potential energy, and electric field?
0
votes
1
answer
227
views
Electrostatic Potential, Potential Energy, Method of Images [closed]
I am a beginner in problem solving in the field of electrostatics. Well equipped with basic strategies and use of gauss' law. I wanted to analyze the situation below and couldn't wrap my head around (...
- 13
0
votes
0
answers
162
views
Hooke's law and elastic potential energy [duplicate]
A mass $m$ is attached to a vertical spring of elastic constant $K$ and length $L$. The spring is supposed to be of negligible mass. Due to the attached mass $m$ the spring reaches a new ...
1
vote
1
answer
70
views
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.......
1
vote
1
answer
2k
views
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.
- 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 ...
- 185
0
votes
2
answers
353
views
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 ...
- 101
-1
votes
1
answer
193
views
Potential and Kinetic equality with scalar and vector potentials
I have to prove that:
$$\frac{d}{dt}\left( T+q\phi \right)=\frac{\partial}{\partial t}\left[ q\left( \phi - \vec{v}\cdot\vec{A}\right)\right] $$
Where $T=\frac{1}{2}mv^2$ is the kinetic energy and ...
- 211
2
votes
1
answer
720
views
What is the electric potential energy of a system of 2 charges? [closed]
If we have two charges of +1C a distance of 1m apart, then if we fix one and bring the other from infinity, the work done = +k. Now, if we fix the other one and bring this one from infinity, the work ...
- 254
2
votes
2
answers
279
views
Assuming strong Newton's third law, why is $\nabla V(\vert {\bf r}_i-{\bf r}_j\vert)=({\bf r}_i-{\bf r}_j)f$?
I don't understand how they come up with (1.34). All I know is that $\nabla V_{ij}=-{\bf F}_{ij}$, but I've never seen this scalar function $f$ appear. Has it something to do with the absolute value ...
- 982
0
votes
2
answers
1k
views
Potential at a point on axis of the ring [closed]
Suppose we have to find out potential $V$ at point $P$ in the given figure.
I know that it can be easily done as
$$dV=\frac{k×dq}{\sqrt{(x^2+a^2)}}$$ and integrating $dq$ to $Q$. Where $k$ is a ...
- 293