All Questions
77
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Is gravitational potential energy of body by $mgh$ negative? [closed]
Consider a 15kg object at 1m from earth ground level,
is P.E = 15kg * 9.8m/s^2 * 1m = 147J
or P.E = -Gm1m2/r^2 * h = -9.8 * 15kg * 1m= -147J
after browsing for a while on debate of potential energy's ...
-1
votes
1
answer
65
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How Can there be a Gravitational Potential when there is NO Gravitational Field? [closed]
How does it make any logic that there exist a potential when there is no net field
for example when we have a Hollow Sphere with mass we can find out the the gravitational *potential inside the sphere ...
1
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4
answers
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
2
votes
4
answers
187
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Is the gravitational potential energy of an object on the ground 0? [duplicate]
In class, we were reviewing kinetic and potential energy and my teacher claimed that on the ground, objects have potential energy. However, as they cannot fall further, isn't their gravitational ...
- 539
0
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0
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62
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Why does Newtonian gravity necessarily imply that gravitational potential energy is negative? [duplicate]
Why can't the zero value of gravitational potential energy be set at a different point instead of infinite distance within Newtonian gravity?
I am not asking why is gravitational potential energy ...
- 476
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
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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
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2
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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
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
0
votes
1
answer
75
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What is the significance of a reference point in calculating the potential?
The gravitational potential is given as $$U(r)=-\frac{GMm}{R}$$ where $G$ is the universal gravitational constant $M$ is the mass of the earth and $m$ is the mass of an arbitrary object and $R$ is the ...
- 335
0
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1
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47
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What happens if we define the gravitational potential zero point at a finite distance? [duplicate]
Two questions.
Can we, and if so how do we define the gravitational potential of a mass (say the sun) to be zero at a finite distance (say 1 light year)?
How does this change the gravitational force ...
- 47
4
votes
3
answers
1k
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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
4
answers
124
views
Is it correct to say, any object has a huge amount of potential energy?
Let's say if it is a $ 1 kg $ metal ball.
Now if we consider it together with a planet some 500 light years away (or if we consider Neptune), then there is potential energy between this metal ball ...
- 332
0
votes
3
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160
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Potential energy $= -GMm/r$ then how could potential energy ever be positive? [duplicate]
Using the $U = -GMm/r$ where $r$ is a distance which would be positive how could potential energy ever be positive?
How could it be positive according to the equation $mgh$?
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