F=G*M*m/d*d. take the case of centre of earth. "d"between us n the earth is 0, then won't force be infinity?!

Question

u must be knowing any number /0 is not defined. so what would happen to the attraction b/w us and the earth? look kinda similar to black holes. gravity becomes infinity? not defined? plz explain.

Answer 1

At the centre of the earth you would be surrounded by equal quantities of mass on each side, so logically you would expect gravity to be zero. to get around the problem of dividing by zero then pick a different fram of reference - split the earth into two and consider the attraction of each half of the globe - then your distance to the centre of mass of each hemisphere is non-zero, but the net gravitational force is zero, as each half of the world is pulling with an equal magentude in opposite directions.

Answer 2

Earth is huge object. So it's mass is distributed in a huge area. By taking that the distance is measured from the centre, we make a assumption that the whole mass is concentrated in the centre and we are situated outside the mass distribution. When one goes inside the earth the whole mass doesnot attract him. Infact a detail calculation for variation of acceleration due to gravity (avilable in any text book of class 11 standard of India) shows that when we reach at a depth h from the surface of the earth the acceleration due to gravity is g(1-h/R), R is the radious of earth and g is the acceleration due to gravity at the surface. So at h=R acceleration is 0 and force=mass*accleration is obviously 0.

Answer 3

Nope.

Pretty easy to understand. If you want to get closer to the center of the Earth, you're going to have to dig a hole, right?

The deeper you go, the more of the Earth's mass is actually not attracting you, but pulling you up, because it is above you.

So when you get to the center, the "M" in the equation is actually zero.

In any case, that equation would not be applicable to such a case, you'd need to integrate the forces exerted on you by all the mini bits of Earth above / around you.

Never forget that an equation is always associated with a domain where it is valid. In this case, the equation typically assumes that you're not trying to get inside one of the two bodies.

Hope this helps

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Answer 4

The distance between us and the center of the Earth isn't zero; it's the radius of the Earth: 6373 km. If you were at the center of the Earth, this still wouldn't be a problem. It turns out that if you calculate the net gravitational force of a hollow sphere from anywhere inside it, it's zero. At the center of the Earth, you're surrounded by what amounts to a series of hollow spheres, so there's no net gravity, even though you are at a distance of zero from Earth's center. The intense pressure, now that's a different story.

Answer 5

F=Gm/d*d would probably suffice

m stands for ur mass

ur own force will keep u intact inspite of jerks caused by wobbling of earth.

u will wobble at ur own and not becouse of earth.

Further to add;

The theory of gravity seems to be confusing. Some ppl may feel that gravity at the centre of earth might be nil becouse gravitational force from the opposite segments of earth is cancelled out (neutralised) at the centre. Some others strongly feel that gravity from opposite segments doesnot get cancelled out. In case the later hold true than gravitational force at the centre will be greater than zero and may be even either equal (GM/r^2) or half of the equal (GM/2*r^2) to that on the outermost surface of earth. The value may also be diffrent when we take into account diffrent aspects of it.

Answer 6

When you are right inside the earth, that is at the centre, you are surrounded by mass all around you .If you consider one segment of earth pulling you towards its centre , the segment opposite to it exerts a force in the opposite direction ,The net force due to these opposite segments get cancelled out . In this way ,for the force due to one segment there is a force due to the opposite segment . The net gravitational force is zero .
The formula F=G*M*m/d*d holds good only when you are outside the earth or atleast on its surface .When you are outside , d= distance from you to the centre of the earth .When you are on the surface d=R , the radius of earth
But when you are inside the earth say at a depth 'd' from the surface, the gravitational force due the portion(like a doughnut) outside you need not be considered .This is because, as I explained earlier for each portion of doughnut there is a portion opposite exerting an equal and opposite force . The force due to the rest of the earth is proportional to (1-d/R)where 'd' is depth and R is radius of earth.
So you see that when d=R force is zero !

Answer 7

as i say here the maths do not agrre with physics. think it another way . imagine that you are in the center of the earth, or to make it easier let us consider a point with the mas of the earth..samll point huge mass. if you were attach to it and someone had to pull you away for a distance d away from it he would need to spend some nergy to do so. therefore you know the distnace you know the work you may find many things from it. then agian why think earth an a body. think simpler.two balls touchning each other. the attractive force between them is great but you can stil break them apart. the attactive force in these case is maximum but not infinite.

Answer 8

the newtons equation is not a rigid equation in which u just substitute the mass of the body u r dealing with(in this case the earth)in place of M...the M is variable as it is the mass enclosed by a symmetrical sphere at the surface of which u r trying to find the gravitational field(or for that matter any other conservative force field)..when one is at the centre of the earth,the mass enclosed by such a sphere is zero.so M in this equation is 0...thus f=0..its basically the Gauss's law of fields(see gauss's law of electrostatic fields)....

Answer 9

d is the distance between centers of two bodies. So it can not be zero from your body's center and that of the Earth, when you are on its surface. Even when you are very close to the Earth's center, the mass surrounded by that distance will be very small to experience large forces.

When distance is zero, i.e two centers coincide, the mass M is also zero and hence no Gravitational force.

Answer 10

If u get to reach the centre of earth, then u might be oscillating back and forth throught the centre of the earth..Something like explained in Hooke's law