Why is gravity called a weak force?
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The force of attraction between moon and earth is 2.3 x 10^ 20 newton (very strong);\n\n between earth and a molecule of oxygen~ 5x 10^ (-25) newton (weaker);\n\n between two oxygen molecules touching each other ~2x10^ (-42) newton; (weakest).\n\nThe electrical attraction between a hydrogen atom’s nucleus and its single electron is 9x 10^ (-8) newton, whereas the gravitational attraction is only 4x10^ (-47) newton.\n\nThe force of gravitation is negligible only in the case of interaction between elementary particles. \n\nONLY WHEN IFTERACTION BETWEEN ELEMENTARY PARTICLES ARE CONSIERED GRAVITATIONAL FORCES ARE WEEK.\n\nHence it is not correct to call gravitational force as week force.\n\nThe force of attraction between moon and earth is 2.3 x 10^ 20 newton (very strong);
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The reason for that is simple.\nAll fundamental forces work on objects carrying a specific type of charge, as in electrical charge, weak charge, colour charge....\nThe charge for gravity is mass. And unlike other of these charges it has only one type (maybe predominantly) - positive mass. For that reason, there is no chance for masses to cancel each other out like when you have a positive charge and a negative charge and together the objest (an atom, for instance) is neutral electrically\nI'm not sure about the weak charge though. Weak forces have a limited range because the bosons that carry them are heavy and can't go far, because of uncertainty (I'm not going into this deeper)\nBottom line: gravity works long range because all masses add up and not cancel each other out.
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hmm....by power I'm pretty sure you are just asking what causes the "attractive force" of gravity? .... the short answer is that matter itself (objects with mass) impose a curvature on the surrounding spacetime which we feel as the attractive force of gravity. \n\nThe more complicated answer is that a quantam theory of gravity would have to be eventually discovered as to make gravity consistent with the other three forces now explained by quantum mechanics..(electromagnetic, weak, strong). Each one of these forces is mediated by an associated particle (electromagnetic- photon, weak-w boson, strong- gluon). The problem is that at the current time no one has ever found the theorized graviton which would be the force mediator for gravity. It has also been speculated that the idea of "mass" is itself mediated by a particle known as the Higgs Boson. This particle along with the graviton would go a long way to explain the most familiar force in our daily lives... but the most mysterious as far as science is concerned.
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Your experimental model is corrupt in terms of current known information about matter and energy in a space-time continuum.  No prediction or calculation can be applied.\nWith two point masses, the only force in the system would be do to gravity.  This is an assumption based upon multiple moving masses in what we would call the normal physical universe.\nIf the distance between their centers (d) was sufficiently small, the points would be touching one another and no force would be exerted on the masses.  If the distance was sufficiently large, then it is possible that the force would be so small that the masses would not move.  Only in a finite range of distances would any gravity possibly exist.\nOne can make no assumptions about G as a gravitational constant, since G assumes that one of the masses is the earth.  One would need additional information about the masses to solve the problem.
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gravity, strong force, weak force, and electromagnetivity
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No, because gravity is inflicted by the mass of an object... and we have a very massive object near by that will outweigh any gravity caused by a humble golf ball or a slightly proud bowling ball: it's called the Earth.\n\nBasically, gravity is a force of attraction, so a large object will attract a small object. That is what keeps the moon orbiting the Earth, and the planets orbiting the Sun. Even here on Earth objects are attracted to each other, but the Earth's gravity makes that force almost impossible to measure or detect.
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Gravity is a force of attraction that acts between bodies that have mass. It is a physical phenomenon of fundamental importance, profoundly affecting the workings of the world around us and the universe beyond. Most familiarly, it is the gravitational attraction of the earth that endows objects with weight and causes them to fall to the ground when dropped. In fact, gravity is also the reason for the very existence of the earth, the sun and other celestial bodies; without it matter would not have coalesced into these bodies and life as we know it would not exist. Gravity is also responsible for keeping the earth and the other planets in their orbits around the sun, the moon in its orbit around the earth, for the tides, and for various other natural phenomena that we observe.\n\nIn common usage "gravity" and "gravitation" are either used interchangeably, or the distinction is sometimes made that "gravity" is specifically the attractive force of the earth, while "gravitation" is the general property of mutual attraction between bodies of matter. In technical usage, "gravitation" is the tendency of bodies to accelerate towards one another, and "gravity" is the force that some theories use to explain this acceleration.\n\nGravity was rather poorly understood until Isaac Newton formulated his law of gravitation in the 17th century. Newton's theory is still widely used for many practical purposes, though for more advanced work it has been supplanted by Einstein's general relativity. While a great deal is now known about the properties of gravity, the ultimate cause of the gravitational force remains an open question and gravity remains an important topic of scientific research.\n\nContents [hide]\n1 Overview of the history of gravitational theory \n2 The Earth's gravity \n2.1 Comparative gravities of the Earth, Sun, Moon and planets \n3 Mathematical equations for a falling body \n3.1 Gravitational potential \n3.2 Acceleration relative to the rotating Earth \n4 Gravity and astronomy \n4.1 Self-gravitating system \n5 Practical uses of gravity \n6 Newton's law of universal gravitation \n6.1 Acceleration due to gravity \n6.2 Bodies with spatial extent \n6.3 Vector form \n6.4 Gravitational field \n7 Problems with Newton's theory \n7.1 Theoretical concerns \n7.2 Disagreement with observation \n7.3 Newton's reservations \n8 Einstein's theory of gravitation \n8.1 Experimental tests \n9 Comparison with electromagnetic force \n10 Gravity and quantum mechanics \n11 Alternative theories \n11.1 Recent alternative theories \n11.2 Historical alternative theories \n12 Notes \n13 See also \n14 References \n15 External links \n \n\n\n[edit]\nOverview of the history of gravitational theory\nThe first mathematical formulation of gravity was Isaac Newton's law of universal gravitation, published in his 1687 work Principia Mathematica. Professor William Whewell of Cambridge University, author of History of the Inductive Sciences (1837) stated:\n\n"The law of gravitation is indisputably and incomparably the greatest scientific discovery ever made, whether we look at the advance which it involved, the extent of the truth disclosed, or the fundamental and satisfactory nature of this truth." [In A Treasury of Science ed. Harlow Shapley et al, Harper & Bros. NY: 1946] \nAlthough the law of universal gravitation was first clearly and rigorously formulated by Isaac Newton, the phenomenon was observed and recorded by others. Even Ptolemy (c. 100-178) had a vague conception of a force tending toward the center of the Earth which not only kept bodies upon its surface, but in some way upheld the order of the universe. Indian astronomer Brahmagupta (598-668), who followed a heliocentric solar system, was the first to recognize gravity as a force of attraction. He explained that "bodies fall towards the Earth as it is in the nature of the Earth to attract bodies
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But...blasting matter in the direction of gravity's pull IS propulsion! :)\n\nYou can't get any "work" without expending energy of some sort.  There's no way to move anything without using some sort of energy.  Perhaps one day that will involve anti-gravity devices, but they'll have to use anti-gravitons in some way to work, which will involve imparting energy to the anti-gravitrons, which will be propulsion (just a different kind).\n\nThe problem with gravity is that it's pretty weak compared to the other fundamental forces.  The weak nuclear force is millions of times stronger that gravity, which means its anti-force is also milltions of times stronger.  Gravity works well for pulling large masses together into planets and stars, but on a small local level it's not that usable...there will probably be better ways to getting about than anti-gravity.
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The gravitational attraction is felt between any two objects (assuming that they have mass).  Gravitation is the weakest fundimental force, so the attraction between two 60 kg persons sitting 6 meters apart is 6.67 nN.\nTHe bad news is that you can't prevent this force from acting, however it is a very small force.  I don't think you need to worry about gravity as the source of your 'physical' attraction.
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Einstein alluded about forces saying that they are fictitious.This make sense because forces do not exist unless there is an interaction between two entities.\nThe magnetudes of interaction depends on the densities of the masses and their volume.The greater the densities the greater the interaction.Thus we can categorize them.\nHowever ;the mechanisms involved is the same in all interactions!Einstein Related this mechanism to a curvature.\nHe had discovered when a force comes into being it comes  from a common  mechanism(.A force is a force ). Force only come into being only as pairs.A force cannot exist by itself no more than a magnet having a single pole.\nUnfortunately ,He had the basis for a Unified Theory and did not realize it.\nAs far what has been measured in the interaction of micromasses or micromasses,I  dont believe there is anything exact.Only approximtions.\nThe phenomena of gravity apply to both micromasses as well as Macromasses.This is the only thing that is Realistic.\nIn other words Electrical phenomena as well Gavity are all one and the same Phenomena.\nYou may not agree with it but its a more realistic answer than resorting to the aphabetic soup of forces that the Physists have concocted as saying that they are different Phenomenae.\nIf you dont understand about their description of weak,strong nuclear forces, dont feel bad. I doubt that they fully understand it themselves!
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Weight is a unit measure of gravitational force.
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Gravity is a property of all particles that possess mass. It is just a fundamental force that at the present can not be explained scientifically to a complete extent.\n\nAny particle that possesses mass (which is basically everything apart from light) has its own gravitational potential which stretches off into infinity. Any other mass which enters this field is subjected to a mutually equivalent force. Obviously then, all matter in the universe is simultaneously interacting with all other mass\n\nIt is proposed that a particle called the graviton carries the force between all massive particles, however this has yet to be identified.\n\nAnother theory is that gravitational waves are constantly being emitted by all objects, and these carry forces.\n\nEinstein proved in his general relativity paper that the presence of mass curves space time and what we observe as a force is merely a particle taking the shortest route through space. This is the current view of gravity\n\nGravity is made purely by the presence of mass, exactly what 'form' it takes is not yet proved.
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Gravity is a force which keeps you stay in groud. For instance if you drop a pencil it falls to earth, if you through a ball to sky the gravity slows the upward thrust give by you to the ball & then pull it back to ground. Like this you can gine "n" no. of examples
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There isn't gravity "on the moon"; gravity is a property of objects. And the self-congratulatory tone of the guy who says you must have realized that your premise is wrong betrays the fact that his answer is a tautology. The only reason the moon exerts a gravitational pull is BECAUSE of its mass. If there were no mass, there would be no gravity in the first place. One can overcome the force of gravity, but saying that the moon would fly apart without it doesn't make any sense. Gravity will be there no matter what. Other forces can overcome it (otherwise the Apollo astronauts who landed there wouldn't have been able to leave its surface), but gravity can't be turned on and off.  In a less dramatic way, one could see the astronauts picking up rocks, or kicking up dust. The kinetic energy of their movements was enough to overcome the force of gravity on the moon until the dust settled (which it does much more quickly than it would on earth, since the dust doesn't encounter friction with air).\n\nNo one knows exactly what gravity IS, by the way. Some physicists believe that it results from the warping of space-time; others continue to seek out a particle (the "graviton") that is the conduit of the force (kind of like "photons" are particles of light).
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Hi, its not gravity but a force opposite to gravity that prevents a boat from sinking and keeps an airplane in the air. Sorry, but I forgot the name of the force, I think it begins with a B. O, the second person said it- Buoyancy.
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In the context of molecular mechanics, a force field (also called a forcefield) refers to the functional form and parameter sets used to describe the interactions (potential energy and forces) within a system of particles (atoms or similarly sized objects). It is independent of the system's electron configuration. A force field can be empirical, derived from higher-level modelling (e.g. quantum chemical studies), or even heuristic.\n\nThe name "force field" is a bit of a misnomer, because the "force fields" are actually potential functions, and the actual physical force field is a negative gradient of the potential.\n\nIn physics, gravitation or gravity is the tendency of objects with mass to accelerate toward each other. Gravitation is one of the four fundamental interactions in nature, the other three being the electromagnetic force, the weak nuclear force, and the strong nuclear force. Gravitation is the weakest of these interactions, but acts over great distances and is always attractive. In classical mechanics, gravitation arises out of the force of gravity (which is often used as a synonym for gravitation). In general relativity, gravitation arises out of spacetime being curved by the presence of mass, and is not a force. In quantum gravity theories, either the graviton is the postulated carrier of the gravitational force.[1], or time-space itself is envisioned as discrete in nature, or both.\n\nThe gravitational attraction of the Earth endows objects with weight and causes them to fall to the ground when dropped. Moreover, gravitation is the reason for the very existence of the earth, the sun and other celestial bodies; without it matter would not have coalesced into these bodies and life as we know it would not exist. Gravitation is also responsible for keeping the earth and the other planets in their orbits around the sun, the moon in its orbit around the earth, for the formation of tides, and for various other natural phenomena that we observe.
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This is a very good question. Ultimately it comes down to being one of the fundamental features of our universe. But it can also be broken down a bit.\n\nLike charges repel, and opposite ones attract because of differences in their electric fields. But the electric fields are really part of the larger electromagnetic force. This force is mediated by photons (light) and, indeed light is a self-propagating electromagnetic wave.\n\nBut there are also three other fundamental forces: gravity, the strong nuclear force and the weak nuclear force. The strong nuclear force is well, strong, but very short range. It holds the protons and neutrons together in a nucleus (otherwise the like charges from the protons would break up every nucleus except hydrogen). The weak nuclear force is sort of a miscellaneous, and comes into play in certain radioactive decay sequences.\n\nIn the 1980s it was shown that the electromagnetic and weak forces are actually the same thing. The difference we observe is that the universe is, relatively speaking, "cold," and these two parts have separated out. It is sort of like having a glass of steam (one thing) which cools down until there is water and ice (two things). The water and ice look a lot different from each other, but are fundamentally the same. In the same way in the very, very early universe when things were a lot hotter, the electromagnetic and weak forces were identical - like the steam in the analogy.\n\nMore recently it was found that the strong force can also be linked to the "electroweak" force in the same sort of manner. The mathematical and physical details are different from "electroweak unification" but the basic principle is the same. It was from this Grand Unification of the electromagnetic, weak, and strong forces the the theoretical notion of quarks came. This GUT has been tested and the experiments show it is right on target.\n\nThe next step is to connect the electro-weak-strong force with gravity. This is a lot harder because the first three are understood in the context of Quantum Mechanics and gravity is understood with General Relativity. QM and GR are not compatible on some basic principles.\n\nOne approach that is being tried to combine QM and GR is with string theory. To make this work the universe is composed of 11 dimensions, the usual 3-spatial and 1-temporal dimentsion, plus 7 very, very small spatial dimensions. If these extra 7 are looped around themselves so that they are vastly "smaller" than a proton, we'd never really notice them.\n\nWhat string theory seems to suggest is that there are just some ways to make stuff in the universe, and one of these ways is to create the "force particles" that mediate the fundamental forces.\n\nSo, extrapolating that, and realizing that string theory is in no sense proven, we can say that "like charges repel" because of the geometry (the 11-dimensions) of the universe.\n\nBut string theory remains far from being complete mathematically, and no one can really make solid predictions yet to test it. So, you can also fall back on the answer in the first paragraph.