All Questions
Tagged with energy potential-energy
480
questions
77
votes
8
answers
27k
views
Does a thrown ball have kinetic energy at the top of the curve?
I'm going through physics with my 5th grade child. There is a question and answer that indicates that a airborne ball at the top of the trajectory does not have kinetic energy.
The diagram below ...
- 977
58
votes
15
answers
13k
views
When a balloon pops and lets a brick fall, where does the energy come from?
Let's say a scientist attaches a 1 kg brick to a large helium inflated balloon, lets the balloon go, and then it reaches an altitude of 10 000 meters before it pops, dropping the brick.
The brick ...
- 1,298
34
votes
5
answers
16k
views
Heisenberg Uncertainty Principle Applied to an infinite square well
I appreciate the statement of Heisenberg's Uncertainty Principle. However, I am a bit confused as to how exactly it applies to the quantum mechanical situation of an infinite square well.
I understand ...
- 988
31
votes
10
answers
8k
views
How is energy "stored in an electric field"?
My physics teacher told me the statement "The energy of a capacitor is stored in its electric field".
Now this confuses me a bit. I understand the energy of a capacitor as a result of the ...
- 492
23
votes
11
answers
4k
views
Is concept of entropy really indispensable? Especially when the concept of potential energy can serve the purpose?
We see that all the natural systems aspire for minimum potential energy state and we also see that all the natural systems also aspire for maximum entropy state. Now from this understanding it seems ...
- 2,517
16
votes
3
answers
6k
views
Do all forms of energy fall under kinetic and potential energy?
I know that energy is recognized through motion. Even in the mass-energy equivalence a velocity is present even though it is a rest-energy (Not really sure if this would count as a potential energy ...
- 551
15
votes
2
answers
2k
views
Is there a fundamental reason there are two distinct types of energy?
There are many forms of energy commonly encountered in physics: chemical, thermal, sound, electromagnetic, nuclear, gravitational, etc. But if you drill down, they are all either:
Energy of motion - ...
- 510
15
votes
2
answers
5k
views
How is energy stored in magnetic and electric fields?
We say that there is energy associated with electric and magnetic fields. For example, in the case of an inductor, we give a vague answer saying that an energy of $\frac{1}{2} LI^2$ is stored in the ...
- 7,203
14
votes
5
answers
8k
views
Does potential energy of an object increases its relativistic mass?
I know that in relativistic condition the increase in kinetic energy of an object increases its relativistic mass as $$m=\frac{m_0}{(1-v^2/c^2)^{1/2}},$$ and mass is another form of energy.
So my ...
- 141
14
votes
1
answer
3k
views
What do we mean when we talk about Gibbs Free Energy?
Before I start, I'm aware that this question may be better suited on the Chemistry or Biology site, but it's my belief that physicists are more likely to have a clear understanding on what certain ...
- 1,760
12
votes
3
answers
152k
views
How does one prove that Energy = Voltage x Charge?
We know
$$E = q V$$
where $E$ is the energy (in Joules), $V$ is the potential difference (in Volts), and $q$ is the charge. Why is this equation true and how we prove it?
- 829
10
votes
3
answers
4k
views
Can an object falling in vacuum generate electricity by itself?
When an object falls through vacuum, gravitational potential energy is converted to kinetic energy. Is there some way to get electrical energy out of the equation by itself (i.e. somehow convert the ...
- 277
9
votes
2
answers
355
views
What can be known about the formulas for energy only from the fact that it is conserved?
The question is to figure out how the energy can be derived knowing just one thing:
There is a quantity called Energy that is conserved over time.
The goal is to get an equation that somehow ...
- 1,760
9
votes
1
answer
4k
views
Feynman Lectures: Why a non-reversible weight lifting machine cannot lift higher that a reversible one?
Consider weight-lifting machines—machines which have the property that they lift one weight by lowering another. Let us also make a hypothesis: that there is no such thing as perpetual motion with ...
- 2,983
8
votes
7
answers
3k
views
Does energy have a sign? [duplicate]
Quantities like position and time allow us to place our origin anywhere, but can the same be said for energy? I was thinking about the way we have defined the quantity gravitational potential, and for ...
user154527