All Questions
Tagged with conventions potential-energy
212
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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
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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
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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 ...
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2
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4
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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 ...
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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
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2
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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
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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
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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
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3
answers
78
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Sign of work done by spring force [closed]
Two similar springs P and Q have spring constants $K_p$ and $K_q$ such
that $K_p>K_q$. They are stretched by the same amount. Compare the
work done by the springs. (NEET 2015)
$$W_p=-\frac{1}{2}...
- 347
1
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2
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80
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Confusion in definition of Potential Energy
Potential energy is defined like this. $ΔP.E=-W_{AB}$. This means that the potential energy at point A minus potential energy at point B should equal the negative of the work done by a conservative ...
- 122
1
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1
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103
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A contradiction in the derivation of electrostatic potential energy? [closed]
I am a 12th grade high school student with no knowledge of vector calculus and more advanced physics.. so if possible, please try to refrain from using advanced concepts which I do not understand.
...
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2
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43
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Expression for Potential energy of a hanging mass
If the acceleration due to gravity is $g$ and a mass $m$ is hanging from a fixed support with a thread of length $l$, then it's potential energy ($U$) is given by:
$$U = -mgl;$$
This was stated by my ...
user355398
1
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4
answers
160
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Minus sign in Force potential relation, a convention?
The usual defination of force in terms of potential energy is
$$\vec F=-\nabla U$$
This definition leads to
$$K_1+P_1=K_2+P_2\rightarrow \Delta K + \Delta P =0$$
Where $K$ and $P$ are kinetic and ...
0
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1
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75
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What is the significance of a reference point in calculating the potential?
The gravitational potential is given as $$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 ...
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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 ...
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