Does gravity increase in strength the closer you get to the center of the earth or any other celestial body?

Question

I feel that the crust of the earth is a very small fraction of the earths total mass. The core of the earth in the size of a car or small house could be 80% of the earths total mass. If gravity does increase the closer you get to the center that would give the theory some credibilty.

Answer 1

No. As a matter of fact, because the gravity starts to act on all sides and counteract itself, at the center of the Earth you'd actually be in free fall, floating there suspended by the equal gravity on all sides. That's if there's any space to float in, of course; while there is no gravitational acceleration at the center of the Earth, there IS a lot of heat and pressure, and the area is occupied by lots of iron and other metals.

Answer 2

Yes (if we follow your assumption), we know this from Newton's law of gravitation. Gravity is an inverse-squared field that gets more powerful the closer you get to it's center (if treating it as point mass, unfortunately we cannot treat the Earth this way).

F = GMm/r^2 ... the smaller r is the bigger F is.

Mind you, if you assume the core to be 80% of Earth's total mass then you definitely would feel a greater and greater pull as you got closer to it. Most definitely. This is because if you use Newton's law above, it is easy to see that if the greatest amount of mass gets closer and closer it will simply overtake any gravity from lesser mass. At least until you breached the core and moved into its center. The college physics professor is right, ONLY if you assume a uniform mass distribution.

The first guy was wrong completely about one thing and sort of right about another. If you ever got to the center of the Earth, the exact center of gravity actually which would be offset from the geometric center due to mass concentration differences, you would remain in lingo and not move. This is because all the force of gravity of the Earth is pulling you equally in all directions. In actuality, you'd probably be ripped apart by such force... and the immense pressure and heat of the Earth's core... but that's another story.

Answer 3

No. The strength of gravity depends on how much mass is between you and the center of Earth. If you start to tunnel down to the center, there would be less mass between you and the center, and therefore less gravity. At the very center the force of gravity on you would be zero - basically all the particles of earth would be pulling you in all directions equally, and so the net force would be zero. Of course, at the center of Earth you'd also be crushed by the weight of all the particles above you, but that's a different story.

Answer 4

None of the above answers hit the mark.
Gravity increases in accordance with the inverse square law as you approach the body. As you go beneath the surface, (assuming constant density of the body) the inverse square law vanishes and is replaced by a linear decreasing law which reaches a value of zero at the center.

Ergo, from the surface to the center of the earth,

g = 9.8(1 - d/6400) m/s^2

where d is the depth in km and 6400 is the radius of the earth in km.

Answer 5

No, the pull will still be the same... for as long as the Earth or celestial body maintains the same mass... The greater the mass of an object, the greater its gravity.

Answer 6

Yes, but the center itself makes an exception, provided the geometric center is also the center of gravity, which is not granted because of uneven composition of the planet.

Answer 7

Yes

Answer 8

yes...the closer to the center of mass the greater the force of gravity.

Answer 9

no it decresses because there is less stuff between you and the center

Answer 10

yes, i think so