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.

View More On Wikipedia.org
  1. A

    B How does gravitational field exert gravitational force on a body?

    I am not sure if there is in fact a classical description of how it occurs, but I’d like to know if there isn’t too!
  2. S

    I The Evolution of Galactic Scale Cosmic Voids

    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...
  3. Hak

    I Doubts about the relativistic description of electrical interactions

    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...
  4. Lotto

    What is the mass of the Galaxy's core?

    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...
  5. D

    I Inverse Square Law for Black Holes

    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...
  6. bob012345

    I Effect of Nearby Mountain on an Ideal Pendulum

    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...
  7. S

    I Gravitational analog of electromagnetic force

    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...
  8. I

    I Gravity inside an exponential mass disk

    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...
  9. D

    Why is Gravitational Force Proportional to Mass Product?

    why is that the gravitational force proportional to product of masses why not sum of masses or something else .........
  10. C

    Exploring the Relationship between Buoyancy Force and Gravitational Force

    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...
  11. S

    I Exploring the Potential of Vacuum Energy & Gravity

    I was reading this, but am confused: https://nautil.us/the-remarkable-emptiness-of-existence-256323/
  12. ForTheLoveOfPhysics

    Currently spending some time outside observable universe…

    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...
  13. J

    Hollowed out sphere exerting gravitational force

    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...
  14. S

    B Can gravitational force have influence on objects at infinitely long distances?

    Can gravitational force have influence at objects at infinitely long distance? Is gravitational force in the form quantum packets?
  15. V

    How can the force of a normal reaction be electromagnetic?

    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...
  16. R

    B Mathematics involving a gravitational force

    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...
  17. dirb

    Calculating Angle & Speed to Reach Planet's Moon from Station Orbit

    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...
  18. S

    I Gravitational force equation derived from GR

    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...
  19. Lunct

    B Gravitational Force acting on a massless body

    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...
  20. SpectraPhy09

    Gravitational Forces between two masses

    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...
  21. Induana

    Gravitational force equals centrifugal force?

    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.
  22. L

    Gravitational force - I translating the wording into the formula

    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...
  23. Istiak

    Why used $\cos\theta$ for $\text{y}$ axis or, gravitational force?

    >![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...
  24. E

    I Does charging my phone increase its gravitational force?

    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?
  25. Delta2

    B Gravitational force between matter and antimatter

    What is the current scientific consensus on the gravitational force between matter and antimatter. Is it repulsive, attractive or zero?
  26. V

    How to get gravitational force on a gaseous particle?

    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...
  27. O

    B Gravitational force between two masses

    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...
  28. momoneedsphysicshelp

    Work done by gravitational force (new problem)

    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...
  29. J

    Net Gravitational force on an object

    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
  30. E

    How will the equation for gravitational force be changed?

    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...
  31. V

    Tension forces of two wires in comparison to the gravitational force

    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...
  32. Ranku

    I Dark matter gravitational force

    Is there any astronomical indication that gravitational force between dark matter might be weaker than between visible matter?
  33. E

    Calculating Masses Using Gravitational Force Equations

    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...
  34. E

    Question about gravitational force

    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...
  35. S

    Correct statement about gravitational force, field and potential

    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...
  36. J

    I Can we increase an object's gravitational force by adding energy?

    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...
  37. J

    Net gravitational force on an object

    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
  38. J

    Electrical force vs Gravitational force

    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...
  39. M

    Calculate the gravitational force exerted on a 5.00 kg baby

    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...
  40. K

    I Integrating discs to find the gravitational force of a sphere

    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...
  41. A

    B Gravitational force of the Earth and Moon

    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...
  42. S

    Curious about Work done by Gravitational force

    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?
  43. nabil23

    B Is the gravitational force higher than it should be?

    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?
  44. MaximusDecimus

    Introductory Physics - Finding "little g"

    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...
  45. Boltzman Oscillation

    How does a the vertical force of gravity end in horizontal motion?

    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!
  46. DvdP

    I need some help for the verification of an assignment about pendulums

    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...
  47. E

    Finding the net gravitational force with Vector Notation

    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...
  48. K

    B Difference between Gravitational Force and Gravity?

    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?
  49. Phantoful

    Finding the gravitational force over a flat infinite sheet

    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...