What is Gravitational force: Definition and 490 Discussions
Gravity (from Latin gravitas 'weight'), or gravitation, is a natural phenomenon by which all things with mass or energy—including planets, stars, galaxies, and even light—are attracted to (or gravitate toward) one another. On Earth, gravity gives weight to physical objects, and the Moon's gravity causes the ocean tides. The gravitational attraction of the original gaseous matter present in the Universe caused it to begin coalescing and forming stars and caused the stars to group together into galaxies, so gravity is responsible for many of the large-scale structures in the Universe. Gravity has an infinite range, although its effects become weaker as objects get further away.
Gravity is most accurately described by the general theory of relativity (proposed by Albert Einstein in 1915), which describes gravity not as a force, but as a consequence of masses moving along geodesic lines in a curved spacetime caused by the uneven distribution of mass. The most extreme example of this curvature of spacetime is a black hole, from which nothing—not even light—can escape once past the black hole's event horizon. However, for most applications, gravity is well approximated by Newton's law of universal gravitation, which describes gravity as a force causing any two bodies to be attracted toward each other, with magnitude proportional to the product of their masses and inversely proportional to the square of the distance between them.
Gravity is the weakest of the four fundamental interactions of physics, approximately 1038 times weaker than the strong interaction, 1036 times weaker than the electromagnetic force and 1029 times weaker than the weak interaction. As a consequence, it has no significant influence at the level of subatomic particles. In contrast, it is the dominant interaction at the macroscopic scale, and is the cause of the formation, shape and trajectory (orbit) of astronomical bodies.
Current models of particle physics imply that the earliest instance of gravity in the Universe, possibly in the form of quantum gravity, supergravity or a gravitational singularity, along with ordinary space and time, developed during the Planck epoch (up to 10−43 seconds after the birth of the Universe), possibly from a primeval state, such as a false vacuum, quantum vacuum or virtual particle, in a currently unknown manner. Attempts to develop a theory of gravity consistent with quantum mechanics, a quantum gravity theory, which would allow gravity to be united in a common mathematical framework (a theory of everything) with the other three fundamental interactions of physics, are a current area of research.
According to some papers I've found [1], [2] expanding voids can be found inside clouds of denser materials that can cause them to eventually collapse. I have a question about this:
Overdensities generally expand up to a given turnaround radius and then collapse. However, as the elements in the...
I would like help with an issue that I have not yet fully mastered.
Consider a particle resting on a plane, it is subjected to a gravitational force, which can be interpreted as the result of a deformation of space-time.
It remains at rest due to the upward binding reaction provided by the...
It is clear that the speed is constant because dark matter hasa gravitational effect on stars, so when a star is further from the core, gravitational force of it is smaller, but the net gravitational force of dark matter is bigger. So the net force acting on each star has to be the same. So...
When you are calculating the gravitational force between two masses and one of them is a black hole, do you still use the distance to the center of mass as you would in Newtonian gravity to find the force? Or is the distance measured only to the event horizon? Is the inverse square law modified...
Suppose there is a very large mountain adjacent to a pendulum such that there is a horizontal component gravitational force of ##10^{-5}g## acting on the otherwise ideal pendulum. How would one use a perturbation to add that effect to first order?
My initial thought would be to figure an angle...
Is there a gravitational analog of electromagnetic force?
[Apart from the obvious "static" forces, ie electrostatic between fixed charges and gravitational between fixed masses.]
I am thinking of the classic situation of a moving charge (or current) creating a magnetic field which then...
I am trying to understand gravity inside an exponential axysymmetric mass disk with no thickness.
I know there are exact solutions for this case, such as the Mestel disk or the Kuzmin model, but I want to work out a simpler solution.
I am approaching the subject by linear superposition. For a...
Picture below. Both bodies are made of same material but the body placed in water had 2.4 times greater mass. What is the relationship between buoyancy Force and gravitational force between body in water and body in air?I have no clue how to solve this.
I know that body with greater mass has 2.4...
It asked for a snappy title so don’t judge!
I’m here for the physics not the BS. And I’ve checked my Dunning-Krugerness & Confirmation Bias at the door!
In a way I’ve always been fascinated by physics and the biggest of questions but recently I thought I’d jump in and actually participate as...
I solved that the hollowed out mass is M/8, which is correct. I don't understand why it is incorrect to substitute the remaining mass (7M/8) back into the F = G*m1m2/r to produce the force. Why is the solution the force of the whole lead sphere minus the force of the “hole” lead sphere, which is...
I do understand that gravitational the electromagnetic force between two electrons or protons is very large compared to the gravitational force between them. I can see this by looking at the equation of gravitational force (##F= \frac {Gm_1m_2} {r^2}##) and the equation of electrical force given...
It's been more than 60 years since I attended high school, and I am trying to learn and understand concepts in Newton's physics that were not taught and were not part of the school curriculum during the 1950's.
It is my understanding that the current mathematics taught and used in our...
A station is orbiting a planet at a distance R1, a moon is orbiting the planet at distance R2 with the period T. The planet itself has a radius rp and a mass mp. We know that when an object adds its velocity at a point in the orbit, the height of the opposite orbit will increase. Determine the...
Hello everyone,
I know that GR equations are complicated and beyond my scope.
But does GR give a simple gravitational equation: Force (as we know it) as a function of distance? (without any complicated tensors).
- If yes. What is the equation? Does it give us something similar to Newtons...
It's a well known fact that acceleration due to gravity is independent of the mass of the accelerating body, and only depends on the mass of the body it is accelerating towards and the distance from it.
One can prove this mathematically very easily.
F=GMm/r^2 (equation 1)
but also F=ma...
Density of the Sphere = 3M/4πR³
Mass of carved out sphere
= density × 4π/3 × R³/8
= M/8
The position of center of mass of The Sphere
{M(0) - M/8(R/2)}/M-M/8
-R/14
So total distance between centers of the two bodies is R/14 + 3R = 43R/14
So now I found force between the Mass 7M/8 (left out...
Book says that correct answer is d) but I can't understand why. If the result of gravitational and centrifugal force is 0N then there is no force that would keep those objects inside the spacecraft orbiting around the planet. Or am I just completely wrong?
Thank you for your help.
i spoke to my proffesor about it but all he said was to put 1 in m1 and m2... for r^2 since it says to quadruple to just put 4^2
I asked about the G in the equation but he said not to worry about iit and pretend its not there...
>![figure 3.2](https://physics.codidact.com/uploads/B5XdWq6GbB4vwyADQdALaCrC)![figure 3.1](https://physics.codidact.com/uploads/pkmWFgoesvQaiAfv5yKj6ynB)<br/>
>Mass M1 is held on a plane with inclination
angle θ, and mass M2 hangs over the side. The two masses are connected by a
massless string...
If the statement above is correct, I do not understand this concept. I guess by charging my phone I am not producing matter. Does it mean in this case, energy converts to mass (not matter)? Can someone please explain this?
This question is very confusing since I don't see two distinct particles that are exerting a gravitational force on each other. Also to complicate matters, a gas is made of many individual particles and I don't know how to determine the gravitational force on a single particle from so many other...
Hello everyone.
Probably this question is trivial, but nevertheless I am confused about Newtons law of motion:
$$F=G\frac{m_1m_2}{r^2}$$
Now, some sources say, that F is the force between the two masses m1 and m2. Other sources say, that F is the force that m1 exhibits on m2. But isn’t this a...
first to find the force by gravity, it would be
4 kg * 9.8 m/s = 39.2 N
then solve for work using W= F*d*cos(theta)
W = 39.2 N * 3 m * cos 28
= 103.83 J
My confusion is do I use sine or cosine and what angle do I use, the actual angle of the incline or the angle between the mass and the...
First, start off with x and y directional forces
F (Test object 1) - F x(Test object 2)
I need help primarily with finding the horizontal component of the force from object 2. How do I find it and express it?
Thanks
At first, I thought when the rod goes really far away from the particle, then L would approach to zero in a particle's reference view. As a result, the equation will be GmM/d^2. However, I just thought that L just remain as it is regardless of change in d, but not sure...
The correct answer is the second one. I honestly have no idea why this is so. I understand that the right rope has less tension that the left one since it's at a shallower angle from real world experience, but I don't really know why this is so, let alone how the forces compare to gravitational...
F=Gm1m2/r^2
2.67 = (6.67x10^-11)(m1xm2)/25000000
M1xM2 = 1 x 10^18
M2 = 1x10^18/M1 (Equation 1)
From the question stem, we know M1 + M2 = 2.5x10^9 (Equation 2)
So, substituting Equation 1 into Equation 2 we get:
1x10^18/m1 + m1 = 2.5 x 10^9
I'M STUCK FROM HERE ONWARDS... in the solutions...
Hello, I hope you are all very well !
Let's say a man, standing on point "0 m" throws a ball 10 m in the air. The gravitational force goes in the opposite (down (always)) of the action (up): I supposed it's -9.81 m/s².
The same action but this time the man stands on the point "10 m" and the...
I think choice B is correct because when I draw the free body diagram of each object, there are three forces acting on each of them and the resultant force is towards the center.
Choice C is wrong because the net field at center is zero.
I think choice D is also correct because if the...
like a shot bullet or arrow has negligibly more gravitational force than a still bullet or arrow?,
this is what I'm asking,
m=e/c^2
F=Gm/r^2,
thus, F=Ge/(c^2*r^2)
where e represents the (mass of the object + energy added to the object)
thus more the energy, more the gravitational force, even...
I suppose we can just find the net x components and y components and then go from there.
Σ Fx = F(mass 1) - Fx(mass 2)
G* (m^2)./d^2) - something
I'm not sure how to express the component forces of the 2nd mass
Hi,
I have always held (and still do I suppose) the view that gravity is much weaker than the coulomb electrical force due to the fact the equations are so similar you can just compare the constants from each equation showing that the graviational force is many orders of magnitude smaller...
Homework Statement
Astrology, that unlikely and vague pseudoscience, makes much of the position of the planets at the moment of birth. The only known force a planet exerts on Earth is gravitational.
(a) Calculate the gravitational force exerted on a 5.00 kg baby by a 130 kg father 0.200 m away...
I am attempting to prove Newton's shell theorem. There are multiple solutions to this problem, but I am attempting a solution involving adding up the gravitational force of an infinite number of infinitely small disks that are placed together (the discs facing a point mass "m") to form a...
A person of mass 60kg will weigh around 100N on the moon. This is roughly equivalent to the gravitational force on a 10kg object on Earth.
Even if the forces acting on both are about the same, we don't see 10kg objects floating around on Earth whereas a man weighing 60kg can easily float on the...
Homework Statement
I don’t understand why this would relate to cosine and not sine, if gravity is often assiciated in the up and down part of a free body diagram.
Homework Equations Wg=mgdcos(theta)[/B]The Attempt at a Solution
Is it because it would depend on your reference frame?
does the mass on the surface of the planet (in state of rest ) has inside it the same gravitational energy to a similar mass after a free falling above its surface for one entire second?
Hello i am new,
I have written this piece for homework with reference, and wondering how i can write it better.
Maybe i have written too much or too little, i would appreciate some help.
Regards.
Little gLittle g, what is considered as G-Force or Gravitational Force is the force in which...
When a stream of water falls perfectly vertical, some water hitting the surface will disperse horizontally. What is the force that causes this? References would be awesome!
Hello, my name is Django and I live in the Netherlands. I've got an assignment for physics about pendulums and part of this assignment is that I need to verify my result with someone else in a country with a different gravitational force (the gravitational force were I live is 9.813 N/m2). I...
Information Given: In the figure, a square of edge length 17.0 cm is formed by four spheres of masses m1 = 4.70 g, m2 = 2.90 g, m3 = 0.800 g, and m4 = 4.70 g.
Question: In unit-vector notation, what is the net gravitational force from them on a central sphere with mass m5 = 2.90 g? Attempted...
What is the difference between the gravitational force and gravity?
Because I was under the impression that gravity is not a force, but one of the 4 fundamental forces of nature is the gravitational force, so I was wondering what the difference between the two is?
Homework Statement
Homework Equations
F=ma
F=Gm1m2/r2
Gauss' Law?
The Attempt at a Solution
I'm not sure if I should be using Gauss' Law for this question, because I've never heard of it or learned about it. I'm currently taking multi-variable calculus (gradients, vectors, etc.). From what I...