All Questions
40
questions
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4
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75
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Why is work done by force $+mgh$ in the situation of throwing something up?
If there is a particle at point A(at rest) and a force moves it to point B(Above point A vertically)(final velocity = 0 at this point), the work done by gravity is $-mgh$. This I understand as the ...
- 85
1
vote
2
answers
103
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Defintion of gravitational potential
I am not much clear regarding the defintion of "gravitational potential":
Is the work done for bringing the unit mass from infinity to that point by, gravitaional force or external force? (...
1
vote
3
answers
94
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Gravitational Potential Energy Behavior [duplicate]
I had a question regarding gravitational potential energy and escape velocity. I don't really understand the concept of escape velocity. I have been learning it as the velocity required for an object ...
- 19
-1
votes
2
answers
222
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Derivation of the gravitation potential energy and gravitation potential
I have some slight confusing in deriving the gravitation potential energy.
In the image below, it explains that the gravitation potential energy is equal to the work done from infinity to a distance r ...
1
vote
5
answers
246
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Work done in raising an object to a height
When we raise an object to a height $h$, it is said that the potential energy of the object is increased by $mgh$. But isn't the work done by gravitational force $-mgh$?
Then that will essentially ...
- 702
1
vote
2
answers
80
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Confusion in definition of Potential Energy
Potential energy is defined like this. $ΔP.E=-W_{AB}$. This means that the potential energy at point A minus potential energy at point B should equal the negative of the work done by a conservative ...
- 122
4
votes
3
answers
1k
views
Work done by the force of gravity
My question is very similiar to this one: Work done by gravity on falling object does not seem to equal change in mechanical energy
As I've understood it, work is only done on an object if the object ...
- 71
1
vote
2
answers
169
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Gravitational potential energy of a two body system from infinity
In determining gravitational energy of a two body system,we define it as the negative work done by gravitational force in bringing those two bodies from infinity to a distance $r$ with respect to the ...
- 19
0
votes
2
answers
298
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What is the meaning of Gravitational Potential when multiple point masses are involved?
According to Wikipedia "The gravitational potential $V$ at a distance $x$ from a point mass of mass $M$ can be defined as the work $W$ that needs to be done by an external agent to bring a unit ...
- 379
1
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2
answers
1k
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Work done to bring a mass from an infinite distance away
In the notes I received from high school teacher, it says:
How much work is done by the gravitational field of the planet in bringing a satellite from an infinite distance to a position $r$ away?
In ...
- 372
0
votes
1
answer
341
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How can we choose any level for gravitational potential energy to be zero?
In my book, I read that we can choose any level as Zero Gravitational P.E. and measure height of objects above it and call its energy 'mgh'. But by saying that all the points on that level is of zero ...
- 5
1
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2
answers
166
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Why isn't the work done by gravity positive in this situation?
I want to find the work done by the force of gravity to move an object of mass $m$ from infinity to a point $P$ at distance $r_p$ from a body of mass $M$ (that I assume fixed). The formula should be
\...
- 113
3
votes
3
answers
125
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What is wrong with this calculation of work done by an agent bringing a unit mass from infinity into a gravitational field? [duplicate]
Let us assume that a gravitational field is created by a mass $M$. An agent is bringing a unit mass from $\infty$ to distance $r < \infty$, both measured from mass $M$.
The agent is always forcing ...
- 49
0
votes
3
answers
988
views
Why is the gravitational potential energy defined as negative? [duplicate]
It is said that since work is done by the gravitational potential itself , so at a finite distance the gravitational potential energy of the body is negative.
Could someone explain why?
-1
votes
2
answers
321
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The reference point of potential energy
In one dimension (I am not familiar with multivariable calculus), potential energy is defined as
$$E_p = -\int F \ dx$$
This is an indefinite integral, and the integration constant $C$ is involved ...
- 485