All Questions
Tagged with newtonian-gravity conventions
93
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Integrating a dot product gives wrong sign for work done [duplicate]
Consider a point mass which creates a gravitational field. The gravitational force pulls a 'test mass' towards the point mass. Since the displacement and gravitational force are in the same direction, ...
2
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2
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Work Done by Gravitational Force
[Bit a long question]
Here in this question, I need to know clear my doubts on Gravity, more precisely Work done by a Conservative Force(here, gravitational force).
Ok, suppose there is an object ...
- 335
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3
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I've a problem understanding Absolute Gravitational Potential Energy?
My current concept about potential energy is that 'If work is done on a body when it is at a point (taken as zero P.E), it covers some distance. Afterward, when it is allowed to move freely it does ...
- 164
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2
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Deriving gravitational potential energy - why is $r_0 = \infty$?
I'm wondering about some assumptions I have to make in deriving the gravitational potential energy. This arises from the following exercise:
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Since the net force acting on the satellite is ...
- 3,200
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Basic question on gravitational potential energy
When a point mass $m$ is moved in the gravitational field of a central body $M$ from a point $P_1(r_1)$ to a point $P_2(r_2)$, its potential energy changes by
$$ \Delta E = GmM \left( \frac{1}{r_1} - \...
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1
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Contradiction on gravitational potential energy
I was reading the derivation of the gravitational energy of a point mass and I seem to have found a contradiction.
The derivation in my textbook is given as follows:-
Let there me a large fixed ...
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-1
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1
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492
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Which is positive work and which is negative work when an object is lifted upwards by force A when already the gravity is acting on it from below?
If I lift a book upwards,then by which force is the negative work done; is it done by the force effected by me or by the force of gravity which is pulling the book from the ground below??
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Gravitational Potential Energy and Zero Points
I have two questions.
1) The first one has to do with the formula for deriving Gravitational Potential Energy. I learned that, for the derivation of Gravitational Potential Energy given large ...
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6
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Why is the work done in moving a unit mass from infinity to a point (where gravitational field exists) negative?
Gravitational force acts towards the center. Here, while performing work, force is towards the center and displacement is also towards the center, then why is the work performed on the body considered ...
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3
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Derivation of gravitational potential energy
Change in potential energy is $$\Delta U = -\text{Work Done} \, .$$ While deriving the equation for potential energy we just equate the work done by gravitational force with the potential energy and ...
1
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1
answer
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Why gravitational potential is negative, as displacement and force are in the same direction?
Gravitational potential at a point in a gravitational field is defined as work done per unit mass in bringing a small test mass from infinity to the point.
I know that:
By integration, we find that ...
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Why add a minus sign in the formula for gravity?
Why do we add a minus sign in our formula for gravity,
when we might as well choose the unit vector $r_{21}$, instead of $r_{12}$?
I'm just wondering why we choose this convention. Is it because it'...
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For a bounded system, is potential energy positive or negative? Why?
Total mechanical energy is negative. Kinetic energy is 0. Therefore potential energy must be negative. Is it?
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5
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Near Earth vs Newtonian gravitational potential
Newton's Law of Universal Gravitation tells us that the potential energy of object in a gravitational field is $$U ~=~ -\frac{GMm}{r}.\tag{1}$$
The experimentally verified near-Earth gravitational ...
- 343
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Why is gravitational potential negative? [closed]
How can gravitational potential be negative?
Gravitation energy increases as we go higher. How is this possible when it is negative?
Please give an intuitive explanation.
Actually I'm confused by ...
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