Earth has gravitational force ,mud wall doesn't attract objects why???
474558
The wall does attract objects gravitationaly, but gravity is an exceptionally weak force, and is only noticeable to us humans when dealing with extremely massive objects (like planets, for example).  Gravity is so weak, in fact, that all you have to do to overcome the gravitational pull of the entire Earth is jump.
145985
the world is roughly spherical, (a ball) and the reason for this is because something as big as earth pulls itself toogether so that everything falls to the center of the sphere, if there were a substantially eneven spot on the earth (let's say a huge spike 40 miles high) it would most likely fall down into place. I magine a bunch of rocks that are pulling themselves together one rock sticks to the other you have two rocks keep on going now you have three so on and so on. If you take a bunch of weird shape magnets they'll stick together in the shape of a ball because they'll all want to be as close as possible and the only way to do that is a sphere since every point in the surface to the center will give you the same distance. Same as if you pushed clay from every side with equal force it'd form a ball.\n\nDUDE!!! PICK A BEST ANSWER!!!!
335677
You are correct, everything has a gravitational pull on every thing else.  Your brother however is not.  ther must have been other contributing factors like th A&#92;C.
918781
Where is your freebody diagram? There are other forces acting on the block than just gravity...\n\nGood Luck
406946
gravity, which is only effective when the object is really big compared to the speed. the gravity of a beach ball might hold ants if it moved reaaly slow, but it would basically not be moving at all. we can escape earth gravity if we move fast enough - thats how rocket ships get into space.
345655
Gravity is also like another force. it follows Newton's 3rd law. Earth attracts us and we attract Earth.\n\nBut a = f/m. Since our mass is less, we move with greater acceleration. For earth, mass is huge and the effect is negligible.
800535
jinde, hi!\n\nwhat an amazing question!  i remember reading about this somewhere, so it took me so long to research it...\n\nsee, when we talk about weight, it varies from spot to spot in the universe.  you may weigh 60kgs on Earth.  but on the moon, you'd be 10kgs.  on Jupiter, you'd be 600000kgs!!!\n\nwhat we need to discuss is the mass of the object, because that would be the only thing that makes sense on the Galactic scale.  are you ready for the answer?  it's gonna be mind-boggling!\n\nThe Earth's mass is approximately 6,000,000,000,000,000,000,000,000 (6E+24) kilograms!!\n\ni know what you're next question will be?\n\n"How did they measure that?"  i have the answer for you!\n\nthe measurement of the planet's weight is derived from the gravitational attraction that the Earth has for objects near it.\n\nit turns out that any two masses have a gravitational attraction for one another. if you put two iron weights near each other, they will attract one another gravitationally. the attraction is extremely slight, but if your instruments are sensitive enough you can measure the gravitational attraction that they have on one another. from that measurement, you could determine the mass of the two objects. the same is true for two marbles too! but the attraction is even slighter because the amount of gravitational force depends on mass of the objects...\n\nNewton showed that, for spherical objects, you can make the simplifying assumption that all of the object's mass is concentrated at the center of the sphere... and the following equation expresses the gravitational attraction that two spherical objects have on one another :\nF = G * M1 * M2 / R2\n\n    * R is the distance separating the two objects.\n    * G is a constant that is 6.67259x10-11m3/s2 kg.\n    * M1 and M2 are the two masses that are attracting each other.\n    * F is the force of attraction between them. \n\nassume that Earth is one of the masses (M1) and a 1-kg sphere is the other (M2).  the force between them is 9.8 kg*m/s2 -- we can calculate this force by dropping the 1-kg sphere and measuring the acceleration that the Earth's gravitational field applies to it (9.8 m/s2)...\n\nthe radius of the Earth is 6,400,000 meters (6,999,125 yards)... if you plug all of these values in and solve for M1, you find that the mass of the Earth is 6,000,000,000,000,000,000,000,000 kilograms (6E+24 kilograms / 1.3E+25 pounds)...\n\nhope this made sense... and if it did, i hope it was useful to you...\n\ndo write me if you need more clarification...\n\nenjoy!
142200
The density of it causes it to have more mass, making it have more gravity, meaning it attracts to itself more than anything else on earth pulling it to the center.\n\nMore mass = more gravity.\n\nGravity pulls two objects together. We don't see this because things we see it's too small to notice, but say the earth is attracted to the sun and that's what keeps us in orbit, a black hole is made up of material that is VERY dense and that's why it pulls everything in so strongly, so strong even light doesn't escape. \n\nSo the densest layer of a planet is in the center, and the least dense is on the outer, unless another scientific principle outwieghs that one in application.\n\nImagine a block of iron and a bag of dirt, which would you feel pulling toward the earth stronger?\nYou would percieve the block of iron going toward the surface of the earth stronger than a bag of dirt, but if you think about it it's also moving toward the center of the earth. So that's what happens, the metal is in the middle and the dirt is on the surface.
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.
251177
I think,to a good approximation, at the centre you would not feel an appreciable gravitational field from the mass of the earth. \n\nIt's a nice result in physics that if you're on the interior of a spherical shell of mass then you feel no gravitational force. You can think of the centre as being surrounded by layer after layer of spherical shells of radius ~0 up to the radius of the earth.\n\nIf you do the calculation, once you start going interior to the earth the gravitational attraction varies linearly with distance from the centre-going from 9.81m/s^2 at the surface to 0 m/s^2 at the centre.\n\nOutrageous!
258318
This has to do with the laws of gravity... a larger object will attract a smaller one to it.  \n\nits not a constant for all objects however, it depends of the mass of the object being attracted.
221678
the earth doesnt fly towards the sun cuz there r more than one force acting upon it...theres the gravitational pull the sun has on the earth as well as the fact that the moon wants to remain in motion in the same direction.this applies to newtons 1rd law of motion(his first law is that an object will remain at rest until acted upon by another object or it will remain in motion until acted upon by an object..in other words,its inertia)...since the earth has both a side movement and the gravitational pull from the sun...those 2 forces cause the earth to orbit around the sun and not fly towards it or away from it. if u dont understand this...email me (pulga0888@yahoo.com) and ill try to explain it better..........now for ur second question...wat makes the earth spin...the earth spins because of the rotation of the magna and stuff in the earths core..well in the convection zone...im pretty sure thats the answer to the second question but im not positive...if u want me to check then email me.
921188
What is the question?  Earth's gravity is a huge subject, best answered with some existing web sites.  I would read the sources below first.
1038202
Because your question is specifically about gravity, I will ignore the temperature of the core. The thing that is important to realize is that gravity is an attractive force. Although it's a bit complicated, we can answer your question by considering gravity an attraction between two atoms.\n\nThe Earth pulls us down as if there were a large gravitational pull coming from the center of the planet, but this is not actually the case. The pull is actually coming from each atom of the Earth independently. It's like if you had two friends who each had a rope attached to your belt buckle. If both are standing in front of you and pull hard, you'll feel a pull that is twice as hard as each alone. If one is standing a bit to the right and the other is standing a bit to the left, and they both pull towards themselves (and they pull just as hard as each other), you will be pulled straight forward.\n\nIn the center of the Earth, it would be like you had lots of friends each with a rope attached to your belt buckle, and they were standing all around you in a circle. If they all pull, they will all cancel each other out -- you won't move at all! You wouldn't even feel it.\n\nSo, to answer your question, in the center of the Earth you would feel pretty much the same as if you were in space -- weightless.
384998
Because gravity acts pretty much in a straight line.  As the swirling dust clouds collected into the earth, the particles acted on each other to form clumps, and the clumbs attracted to each other, then you end up with a nucleus of matter imparting a gravity field radially out from the centre.  Things will be colliding with the nucleus from all directions with an equal probability and thus a sphere.
787952
The force of attraction is given by Newton's law, F = G* m1*m2/r^2, where G = universal gravitational constant, 6.67 * 10^-11 N*m^2/kg^2.  You have the two masses, and the radius of earth is the distance r.  Your weight is the same as the gravitational force.
436928
If the Earth's radius were bigger, and the mass of it stayed the same, then you would weigh lighter.  That's because with a bigger radius, you're farther away from the centre of gravity, therefore less pull.  If the mass change, then the situation would be different.