is it possible for the center of gravity to lie outside the object?
83009
Center of gravity is not a point but is a line of action of force...\nSince a line is of infinite lenght there is no way you can think of the center of gravity of an object which does not pass through the object.\n\nhttp://www.schoolingkids.com/\n\nhttp://www.futureaccountant.com/
887515
Please be warned - there are MANY incorrect responses above.\n\nThe theoretical answer to your theoretical question is that you would be weightless at the centre of the earth because the forces of attraction would exactly cancel out.\n\nTo address some of the errors above:\nYou would not be pulled apart because the mass of the earth is not enough.  Similarly, you are not pulled apart when standing ON the earth, even though the earth is pulling your feet more strongly than your head.  If the earth were enormously massive then you would be (it's called being spaghettified, although it ought to have a different name if you are the centre!).\n\nThe force of attraction does NOT increase as you get closer to the centre of the earth.  The responder is thinking about Newton's Law of Gravitation which applies to POINT masses.  If you apply it to a large body such as the earth then you find that only the sphere underneath you attracts - the rest of it cancels out.  ie The earth is roughly 6400km in radius.  If you are 5000km from the centre then you will feel the force of attraction of a 5000km radius sphere of the Earth at a distance of 5000km - the force of attraction of the remaining 1400km 'shell' exactly cancels out.\n\nYou would not 'feel' the force of the sun (any more than you do on the earth) since its force of attraction is providing the centripetal force required to move you in a circle around the sun.\n\nThe force of gravity is NOT caused by the rotation of the earth.  In fact, if the earth stopped rotating we would all be a little bit heavier since a part of the force of gravity is being used to provide the centripetal acceleration necessary to keep us spinning around once per day, with the earth (on the equator this amounts to about 0.3%).\n\nYou also ask about gravitons!!  How they work is a difficult question since they are theoretical!  According to classical Newtonian theory, gravity is simply a fundamental property of matter - matter attracts other matter and that's that.  Newton himself was always uncomfortable about the idea of "action at a distance" but even his genius could not solve the problem, given the limitations of the time that he lived in.  Along came Einstein and gave a solution - matter distorts the shape of space and the apparent force of gravity is actually simply the result of an object moving in the distorted space.  Think of a heavy ball on a rubber sheet and another ball moving along.  It does not 'know' about the heavy ball but it changes its path towards the ball because the surface on which it is rolling has been distorted.\n\nThe graviton is an attempt to explain the phenomenon of gravity without recourse to considering distortions of space-time.  Bodies with mass emit particles called gravitons.  They interact with other massive particles.  The degree of ineraction can be calculated and reasonably easily represented on a Feynman diagram.  Try an internet search.  Huge tanks full of washing up liquid have been built down abandoned deep mine shafts to try to detect these particles.  Some 'events' have been noted but they remain elusive, as far as I know.\n\nHope this goes some way to answering your interesting questions.
296792
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.
643953
depends on the direction of the force
247359
Mass interacting with gravity
930430
The center of gravity of the cone lies at  one-third of the height from the bottom of the cone.\n\nThe angular elevation of this point from the circular base is given by tan A = h/(3r) where  h is the height of the cone and r is radius of the circular base.\n\nFor the cone to topple the vertical line from the center of gravity must fall outside the circular base.\n\nThat is after tilting the cone the vertical line from the center of gravity must be just more than 90 degree from the ground.\n\nTherefore the angle through which the cone has to be tilted\n is (90 - A.) \n\nA can be found from tan A = h/(3r).
335564
The center of gravity will be different for different people depending on their height or weight or if the have their arm pointing forward or backward etc.  When you stand up from the sitting position all you are doing is changing where your center of gravity is to make it easier to stand.  Speed does not effect center of gravity however acceleration and deceleration does.
119146
No, i dont think gravity can pull in multiple directions, which would be neccessary for something to expand.
393015
If a body is fixed at its center of gravity, it is in a state of neutral equilibrium.\n\nTherefore, the whole weight of the body can be assumed to act at the center of gravity.\n\nThe following method is used to find an expression for the C.G of a solid body.\n\nThe solid body is considered to be broken up into elementary particles.\n\nIf m1, m2, m3 etc are the masses of the particles, their weights are m1g,m2g, m3g etc.\n\nThe weights are acting parallel to each other in the downward direction.\n\nIf we assume that the C.G is at the point X,  and x1,x2,x3 etc are the distances of m1,m2,m3, then the  sum of MOMENTS of all these weights about the origin must be equal to the moment of the whole weight of the body about its C.G.\n\nTherefore,   Mg .X =  ( m1g .x1 + m2g .x2+ m3g .x3 + m4g .x4+ ....) where M = sum of all masses.\n\nIn short, the moments of weights of small particles in a solid body about any point is equal to the moment of the whole weight of the body about its C.G.
844498
You have uncovered one of the secrets of the universe. Simple Harmonic Motion (SHM) surrounds us in every aspect of the universe. It is the lowest common denominator. Even Newton got it slightly wrong in his First Law where he said that a body will continue in uniform motion until an external force acts upon it. There is nowhere in the known universe that gravity does not exist.\n\nConsider an air table which is flat and which extends in all directions by a million miles, and it rests on the earth. place a puck on it and give it a gentle nudge. It will move off in the direction you push it at an apparently constant velocity, however it will eventually stop and return to the point where it started because of the earth's gravitational field. It will shoot past and head off in the opposite direction until it stops again, being pulled back by the earth's gravitational field. It will continue this way forever (ignoring all friction), oscillating in simple harmonic motion. \n\nNewton's problem was that he was restricted to observing a very small portion of the SHM path, so it seemed linear.\n\nAnyway, congratulations, you are on the path to unlocking the secrets of the universe.
383007
Yes, the first part is true.  Why does that make tides more "believable"?  \n Any two gravitaionally-bound objects will orbit around a common center of gravity.  (which is closer to the more massive object).
346914
Yes, especially forward at a rate of 1 sec = 1 sec.\n\nI also believe that other rates are possible depending on velocity and proximity to sources of gravity.\n\nI also would like to believe that it can be reversed, but that's harder to swallow due to paradox effects.
79989
Still more theory than fact.\nIt is responsible for the force of gravity.
954663
it has gravity indeed, but less than earth\n\n:> peace\n.
921247
well somewhere in the middle you might become weightless as you would be in the center of a spinning mass. but most likely you would get to a point that the gravity would push you back. just like on a merry go round getting to the center is actually pretty hard.
169193
you can achieve this with centrifugal force. it is called an orbit. the moon is very close to this point it reappears in nearly the same spot about 25 hours later!
1054239
no it doesn't affect gravity.  it's a double reversal, so everything is perceived right side up.  hold something in front of your face.  then turn it upside down, that's how your eyes see it, flip it around again (notice how it's right side up now?) this is how your brain sees it.\n\nit's all cool, you won't fall off the face of the earth...  ;-)