Questions tagged [newtonian-gravity]
This tag is for questions regarding the Newtonian model of gravity in which the force between two objects is given by $~GMm/r^2~.$ It is a natural phenomenon by which all things with mass or energy – including planets, stars, galaxies, and even light – attract one another. On Earth, gravity gives weight to physical objects, and the Moon's gravity causes the ocean tides.
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Error concerning projectile motion in respected textbook?
In the textbook Fundamentals of Physics by R. Shankar of Yale Open Courses, appears the following assertion pertaining to a car driving off a cliff, which seems correct:
This is exactly how long it ...
Buzz♦
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From my reference frame, why does the Earth need a huge kinetic energy [$0.5M_E(11200)^2=3.75*10^{32}$ joules] to escape me? [closed]
I wake up screaming into the void, when I see the Earth almost touching me but going away from me at 11.2 $km/s$.
I don't remember what happened before I woke up. I faintly recollect being cannoned up ...
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What are the effect of earth diameter increasing by 2 meters? [closed]
I was wondering what will be effect of if earths radius increases just by 2 meters, in two main categories:
Same weight, i.e earth's mass does not change.
Weight change in proportion to volume change
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Why should Apparent weight of the object floating in a fluid is 0?
The buoyant force act on the object and weight of the body act on water, so do they both cancel out?
Now one more thing weight experienced by a body is equal to reaction force acting on a body so here ...
CommunityBot
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Generalization of Feynman's derivation of the formula for gravitational potential energy in FLP volume I
In the Feynman Lectures on Physics, Feynman derives the formula for gravitational potential energy by applying a line of reasoning he borrowed from Carnot on reversible weight lifting machines (FLP I, ...
CommunityBot
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Work done by conservative and non-conservative forces
Work done by conservative forces changes one form of mechanical energy into another. Is it correct to assume that work done by non-conservative forces changes one form of energy to another, for e.g., ...
CommunityBot
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Why is pressure in the outermost layer of a star lower than at its center?
I have done the math and I have obtained the hydrostatic pressure in a star is lower at the outermost layer of a star than in its center, where the pressure is actually maximum. Although the equations ...
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How much time does it take for an object to fall from space? [closed]
Let's say there's an object of mass $m$ in space, $h$ meters away from the surface of the Earth. $h$ is large enough that $g$ cannot be assumed to be constant. The acceleration varies according to ...
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Intuition behind gravitational potential
Gravitational potential at a point is equal to work done in bringing a unit mass from infinity to a particular point
That was the text book definition
$$V_{p} = -\frac{GM}{r}$$
If we calculate $V_p$ ...
CommunityBot
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Gravitational collapse - proof that energy dissipation is required?
As an undergraduate, I took a short course on astrophysics, where I encountered the Jeans mass. This is the critical mass for a spherical cloud of interstellar gas above which the cloud is predicted ...
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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 ...
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Do objects really "fall" at the same rate? [duplicate]
I understand that a hammer and a feather were dropped on the moon and they both landed at the same time. I understand that for all practical intents and purposes all objects do fall at the same rate.
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What is the relationship between gravitation, centripetal and centrifugal force on the Earth?
I'm trying to analyze a situation wherein a ship is moving across the surface of the earth. I am trying to analyze this situation in a reference frame that is rotating with the earth (NED frame).
I am ...
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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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Two particles rotating about their center of mass
Two bodies each of mass $m$ are rotating about their center of mass where the radius is $r$.
Here centripetal force of each body is $\frac{mv^2}{r}$ where $v$ is the linear speed. Now, gravitational ...
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