All Questions
70
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Drawbacks of Quasi-Static process for lifting a block
Definition of Quasi-static: A quasi-static process is a thermodynamic or mechanical process that occurs very slowly, allowing the system to remain in a state of equilibrium at all times.
While ...
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258
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Is impulse functionally equivalent to work and therefore expressible in Joules?
I am trying to understand things at at a fundamental and conceptual level.
Givens...
1 kg mass
Mass is at rest (relatively, of course)
Mass is on an idealized frictionless surface
1 N of force is ...
CommunityBot
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2
answers
48
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Is it possible that work is being done on an object, it's kinetic energy doesn't changes and still the body is transferred from one point to another?
Recently, I read a book about Electrostatics which stated that "Electrostatic Potential at a point is defined as the work done to move a unit charge from a reference point (generally taken as ...
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vote
2
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98
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Why is force "accumulated" more at a higher speed?
I tried to understand why kinetic energy is proportional to the square of velocity. In this endeavor I stumbled upon a book "Emilie du Chatelet: Daring Genius of the Enlightenment" (ISBN 978-...
- 112
-4
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1
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Does every object have an infinite amount of energy? [duplicate]
If energy is defined as the capacity to do work, and the formula for work is force times displacement, if we place an object on a frictionless surface and apply any amount of force to said object, the ...
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1
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319
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How can the Joule be the unit of both work and energy?
Say a person applies 1 N to a box with a mass of 1 kg, displacing 1 m. This is one Joule of work
(1 N for 1 m).
Now say the person applies 1 N to a box with double the mass, displacing 1 m as well. ...
1
vote
2
answers
403
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Work Done on a rotating thin rod by hinge Forces
So I was studying the concept of rotational energy through a video, and the guy presented a problem,
It's like this:
"Suppose a thin rod of mass M and length L/2 is hinged from one end. Then, it ...
2
votes
2
answers
102
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Where does $W = \Delta E$ come from?
My textbook states the following:
$$W_{net}=W_{non−conservative}+W_{conservative}$$
$$W_{non−conservative}=ΔKE+ΔPE$$
$$W_{conservative}=−ΔPE$$
$$W_{net}=ΔKE$$
$$W=FDcos(Θ)$$
However, my teacher states ...
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votes
1
answer
86
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Why isn't work $Fd \sec \theta$? [closed]
In the following image if force the triangle PAN was right angle at P then the component of force in the direction of displacement would be $F\sec\theta$ so work $F*Displacement(AC)*\sec \theta $.
I ...
2
votes
2
answers
775
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How does the work-energy theorem relate to the first law of thermodynamics?
The work energy theorem states that the net work on a particle is equal to the change in the kinetic energy of the particle:
$$W_{net}=\Delta K $$
My first question is whether this formula (the work-...
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1
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79
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Is there a non-counterfactual definition of energy? [duplicate]
I have once heard that the definition of energy is "the ability to do work". However, that is a counterfactual definition, because a physical system can have that ability without actually ...
- 207k
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6
answers
291
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Does potential energy actually exist? Or is it just a useful mathematical model? [closed]
The title basically covers it. I've actually thought about this question for a while now, and I am still not sure if I have a definitive answer. Most potential energies seem to just be the work that ...
- 16.7k
4
votes
2
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How do we justify that work is a "transfer of energy" in the general case?
By the work-energy theorem, we can justify that the work on a particle due to the net force equals the change in kinetic energy of the particle. In compact notation,
\begin{align}\tag{1}
W_{\text{net}}...
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Why do manual treadmills burn more calories than automatic treadmills?
Studies show that manual treadmills burn 30% more calories than automatic ones.
Let's assume that there is no air friction.
The figure is a diagram of the forces acting on a person running on the ...
- 95.6k
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votes
3
answers
88
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Consolidating two ways to calculate work
I was wondering if I could get some help closing some fundamental gaps in my intuition of work, as it relates to force and distance travelled.
Scenario
Say we pull a 1kg box along the ground. We pull ...
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