Tagged Questions
0
votes
2answers
44 views
Kinetic energy of two charged balls at infinite distance between them
If I have two balls with masses and charges $m_1, q_1^{+}$, $m_2, q_2^{+}$, initially held at distance $d$, and then released, how can I know the kinetic energies of each of the balls at infinite ...
3
votes
6answers
339 views
Electrostatic Potential Energy Derivation
How is the boxed step , physically as well as mathematically justified and correct ?
Source:Wiki http://en.wikipedia.org/wiki/Electric_potential_energy
As work done = $- \Delta U $. for Conservative ...
5
votes
4answers
197 views
Energy Gain with capacitor?
I have a question about energy gain in capacitors. Assume the following system:
As the electron gets accelerated inside the capacitor, it will have more kinetic energy coming out than going in. But ...
0
votes
1answer
35 views
About electrostatic potential energy
I consider an electron (charge $-e$) in $x=0$ and a constant electric field $E(x) \equiv E $. If the electron has initial velocity $v_0$ with the same direction of $E$, then its potential energy is
$$ ...
0
votes
1answer
45 views
Gravitational potential energy
Consider two places next to each other: Place 1, where there is a gravitational field whereas Place 2 - there's no field.
Now if we lifted a box in place 1, it gains potential energy. Then, we move ...
3
votes
3answers
193 views
Potential energy in $E_f^2=(mc^2)^2+(pc)^2$?
Let's consider
$$E_f^2=(mc^2)^2+(pc)^2$$
where the $mc^2$ is the rest energy due to the rest mass -- in Finnish "lepomassa".
$$ \sqrt{(mc^2)^2+(pc)^2} - mc^2~=~(\gamma-1)mc^2$$
is the kinetic ...
0
votes
2answers
106 views
Elastic potential
I have a doubt:
elastic potential energy is given by: $U=\frac{k}{2}x^2+K$
but does elastic potential exist? (for example: potential gravitational energy is given by $U=mgz+K$ and gravitational ...
2
votes
5answers
267 views
Is there a mathematical derivation of potential energy that is *not* rooted in the conservation of energy?
For simplicity I'll consider only gravity, but in general this question only applies to conservative forces.
As per my understanding, the way one gets to the equation for gravitational potential ...
0
votes
0answers
413 views
Word problem - Potential/Elastic Energy [closed]
A man (weighing $86\space Kg$) is climbing a mountain when he suddenly
falls. His security rope works like a spring with spring constant $1.2
> \times \space 10^3 N/m$ and after a fall of ...
