Questions tagged [newtonian-gravity]
The Newtonian model of gravity in which the force between two objects is given by GMm/r^2.
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Horseshoe orbit cycle times
I asked on Worldbuilding originally, but was directed here instead
I've been working on a habitable moon system for a story, and I'm now trying to populate the other moons around the parent planet. ...
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Would Newton law of gravity be the same between two neutrons at smaller distance?
Imagine 2 neutrons placed at some distance apart, they should only gravitationally attract each other according to Newton law of gravity. Theoretically the law should work at smaller distance until ...
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Could a non-rotating planet, in a binary situation, have gravity?
Is it possible for a singular planet to rotate around a single sun in the same way that our moon rotates around the Earth? If so, would it be possible for that planet, if as large or larger than ...
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How does the shell theorem play into two objects just outside of a planet's boundaries gravity towards each other?
So the scenario I envision to represent this would be two meteors on opposites sides of a planet heading directly towards the planet. How would the shell theorem play into the two meteors ...
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Motion under central force: the contribution of evenly distributed “dust” [on hold]
A solar system that is consisted of a star with mass $M$ and a planet with mass $m$ ($m<<M$) is in a cloud of evenly distributed "dust".
From Gauss' Law it can be showed that the dust will ...
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1answer
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Phone accelerometer - formula to calculate angular gravity
I am taking readings from the accelerometer of a smartphone and want to account for gravity. My device reports residual gravity as "10g" (device stationary, screen facing up).
As the angle of the ...
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1answer
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Does the Higgs VEV depend on the gravitational potential?
If I take the non-relativistic limit of the Klein-Gordon equation in a curved space-time I will get a contribution from the Newtonian gravitational potential. Shouldn't this gravitational contribution ...
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2answers
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How far can you pee on the moon vs. mars? [on hold]
Let's suppose you are at Elon Musk's Future Mars colony and you drank too much beer, how far can you pee on Mars if you can pee one meter on earth?
If the next day you get on the shuttle to the ...
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1answer
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How does an object's volume affect its gravitational pull?
Two instances. An object is in front of two different planets with the same masses, but two different volumes. How does the gravitational pull vary from each planet? I am thinking with more given ...
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Please explain gravity? [closed]
If spacetime is like an elastic plane holding planetary masses that sink into pockets creating "gravity" and planetary orbits around large masses, then how do we explain the "gravitational force" we ...
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4answers
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Why does the GPE of an object always equal the work done?
I had a question that said, "If you do 100 J of work to lift an object over your head, what is the gravitational potential energy relative to its starting position? What would be its gravitational ...
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3answers
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Difference between center of mass and center of gravity
Let's consider a very tall building (g would be variable) which is rotating with the earth naturally.
Now do the centrifugal force and the gravitational force act on the same spot?
If not why does the ...
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Why doesn't the Earth accelerate towards us?
According to Newton's third law of motion that states that every action has an equal and opposite reaction.
So, if the Earth exerts a gravitational pull on us (people) then even we should exert a ...
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1answer
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How is the normal force on a banked track larger than gravity?
The formula of the vertical force of an object that is not accelerating up or down on a banked curve is: Ncos(θ) = mg
There is also a centripetal force component which shows that the normal force is ...
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How does a Foucault pendulum in an Earth-sized centrifuge precess? [closed]
Imagine replacing Earth with a centrifugal arm length Earth radius and rotating to produce acceleration g.
How does a Foucault pendulum mounted on the end of the centrifuge move and why ?
Ignoring ...
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2answers
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Will the motion in both systems be same?
In my book, the discussion in SHM is mainly about a mass hanging vertically from a spring. But there are some exercises which contain questions which involves a mass attached to a spring and the whole ...
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3answers
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Gravitional Potential Energy Formula Magnitude confusion
It is pretty intuitive that increasing the height or distance of an object and also increasing the mass of it increases the gravitational potential energy (GPE).
Basically the question is asking, ...
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Mass hanging from spring in free fall
Q: A mass $m$ hangs from a massless spring connected to the roof of a box of mass $M$. When the box is held stationary, the mass-spring system oscillates vertically with angular frequency $\omega$. If ...
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1answer
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How fast can we walk? [on hold]
It has been a common observation that as and when we accelerate ourselves, there comes a point after which we cannot stay on the ground completely. I wanted to know whether we can find such a maximum ...
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Force of gravity [duplicate]
I want to know why isn't the moon fall on earth instead of floating on top or going around the earth without even falling on earth by the force of gravity on earth .
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What determines the direction of an object that has undergone the effect of a gravitational slingshot?
I just started researching this topic and therefore I do not know much about it. Nonetheless, I am still curious about what determines the direction an object takes after passing by a planet. I think ...
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Constraints on the mass distribution within each body such that their mutual orbits are Keplerian?
The trajectories of two point masses with respect to their center of mass are conic sections or Kepler orbits.
But what if the bodies have finite size with respect to their separation, and not ...
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2answers
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Calculation of Gravitational Collapse time
The answers to Gravitational collapse and free fall time (spherical, pressure-free) describe the calculation of collapse time for a gas. For the case of neutral hydrogen gas with number density $10^4$/...
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1answer
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Negative Work done by gravity
When we lift an object from ground we say we did work on object . We also say that gravity has done negative work because we did work to overcome gravity . When we did work our chemical energy was ...
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1answer
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Is the Gravity Turn the most efficient way to put a spaceship into orbit?
The Gravity Turn is a maneuver used to put a spaceship from ground into orbit. It can be described as lifting the spacecraft vertically up, then tilting it towards the desired orbit by a small angle ...
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1answer
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If three equal free masses $M$ are at rest at vertex of equlateral triangle of length $R$ at $t=0$.what is relation between position and time? [closed]
I need a equation describing relationship between position of particle and time.You can assume only gravitational interaction between masses.
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If gravitation force varied with $r^{-3}$ instead of $r^{-2}$ what would happen to Kepler's laws [duplicate]
2nd law wouldn't change as it is LCAM. 3rd Law would change. But I'm confused about first law. Does any body under influence of any central force move in an ellipse?Can anyone give a simple proof/...
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1answer
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Effect of wheel location on center of gravity
So, my kids are in Cub Scouts and are racing in the Pinewood Derby for the first time. After a thorough read-through of the rules, there is nothing prohibiting a racer from shifting the rear axle (or ...
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2answers
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Why is the Moon's Centre of gravity different to its centre of mass? [duplicate]
All the places that I've seen an answer to this question simply state that it's because there is a stronger gravitational pull on the near side of the moon, facing the earth. But I'm wondering how ...
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1answer
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Modification of Gravitational force's law and related problem
I'm facing a problem which states the following:
Suppose that it is discovered that Newton's law of gravitation is incorrect and that the force $F$ on test particle of mass $m$ due to a body of ...
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1answer
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If I drive East, how much lighter am I than if I drive West?
I'm at the equator. Suppose I am driving at x kph, in the direction of the Earth's rotation (i.e. due East), I presume that the force my vehicle exerts on the ground is less than when I am stationary. ...
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2answers
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Which force described the “absolute” speed change of the moon in Newtonian mechanics?
In the world of "absolute" speed values in the Newtonian mechanics, the moon must move faster (i.e., must have a higher speed) if he travels with the earth (i.e., has the same velocity direction) than ...
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1answer
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Acceleration: $G$ and $G$s difference
In some literature the acceleration is stated in Gs units. For example, "All structures shall be built to survive 15 Gs of launch acceleration".
However, g-force sometime also stated in G units ...
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2answers
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Shouldn't ball has to move in the circle even after cutting the rope by which it was attached? [closed]
Since the tension force is a central acting force, the torque on an orbiting ball about that center is zero. But if the rope is cut down during motion the torque would still remain zero. This would ...
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2answers
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Does gravity hold electrons in orbit around atomic nuclei? [closed]
If the forces are unified then it must, mustn't it?
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6answers
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Potential Energy and Work [duplicate]
My physics textbook says when a rock is lifted gravity does negative work and increases the gravitational potential energy. My understanding of negative work implies energy is being removed when an ...
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2answers
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Why cannot we go in outer space with constant speed?
Sorry if this question is very childish for experts here. This was the question I had in school and years later it has resurfaced. I did some google search but getting the same equations of ...
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Is the total mechanical energy of a satellite constant, regardless of its orbital radius?
If a satellite moves outwards into an orbit that is at a greater distance from the centre of Earth, work has been done. As work is the sum of the change in kinetic energy and gravitational PE, has the ...
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Gravitational force on a point mass due to a ring of mass
I tried to work out a problem related to gravitational force due to rings.
But it seems like I've got some misunderstandings in the theory.
A point of mass M is on the axis that runs through the ...
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3answers
121 views
If a satellite moves towards Earth, is negative work done against the force of gravity?
A bit confused here - if a satellite approaches Earth, its displacement is in the same direction as the gravitational force (towards the centre of rotation). Therefore, gravity is doing positive work?
...
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6answers
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How is it possible to escape a gravitational body? [duplicate]
The velocity required to escape a gravitational body is termed escape velocity. But how is it possible for any object to escape a body if it's gravitational field acts over an infinite range, so the ...
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2answers
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Constant gravitational acceleration $g$ and energy
I've been taught the $g$ is constant for different masses and that if I were to drop a heavy object and a light object from the same height then they would reach the ground at the same instant with ...
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2answers
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How does gravitational attraction relate to weight? [duplicate]
I understand that gravitational attraction is the attraction of a particle by another particle or matter, which in this case is the earth. But I don't understand why this (gravitational attraction) is ...
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1answer
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Will water spill out of filled capillary tube, if raised from water?
if to raise a filled capillary tube from the level of water, will the inside will spill out? or will it keep stuck inside?
imagine a capillary tube put in water, the water rises inside the capillary ...
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Why do bodies fall identically in uniform acceleration and uniform gravitational field? [duplicate]
In his reformulation of Einstein’s Elevator thought experiment, James Robert Brown (1993) says that an observer in a uniformly accelerating spaceship in space (free of gravitational effects) will see ...
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1answer
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Lagrangian Equation of Motion for Planetary Orbit in a Single Plane
Assume that a mass $m$ is in a gravitational orbit around a much larger mass $M$, as in the case of the earth revolving around the sun. Also, assume the motion is constrained to a single horizontal $...
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2answers
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What is meant by “instantaneously aligned” with regards to rotating reference frames/coordinate axes?
I'm trying to understand a set of lecture notes I found online from MIT which describe the derivation of the equations of motion for an object in a rotating reference frame, this is for an essay on ...
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4answers
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Gravity, falling bodies, and the equivalence principle
Why is that bodies in a box accelerating uniformally in space that is sufficiently removed from gravitational fields fall identically to bodies in a box located in a homogeneous gravitational field (e....
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3answers
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What's the difference between gravitational attraction and weight? [duplicate]
What exactly is gravitational attraction? In my textbook it was quoted " all objects both tiny and large objects are attracted to the earth. This is known as gravitational attraction, or the force due ...
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2answers
75 views
Do comets and meteors attract artificial satellites while passing by?
What will be effect on artificial satellites when comets or meteors come close or pass by?
