在地球核心附近的重力有多大？

[卷機山花]

如果純粹睇牛頓既萬有引力定律，物件係地心受到既重力係無限大，但係我睇過某啲物理既書，佢話係地心度所受既力又係另一種問題，好似係同受力面積有關...但係我唔係好明

[simonii]

物件係地心受到既重力係0

[扒飯撈麵]

understand with the view of physics but not mathematics only

in the case of Earth gravity,
we can consider the earth is a large sphere.
when you get closer to the earth from, the gravition force increase simply with a change of distance until you tiuch the earth surface.

U ->* outer space ->> ( Earth surface ( Earth centre) Earth surface) outer space

*sign of attraction direction , more arrow">" indicate greater force(not in scale)

when you go "inside" the earth, the part of the mass of the earth attact you in opposite direction.
resulting a smaller net attraction.
it is depended on how depth you entred and the mass and density distribution.
Since the high dense materials are mostly in core, the earth crust has about 1/2.5-3 density of the core only

(Earth surface <-U->> (Earth centre) Earth Surface)

When you are at the centre of the Earth, the attraction from the mass of Earth is nearly the same in all direction.
the net gravition force is about 0.

(Earth surface (Earth <<-U->> centre) Earth Surface)

ps although the gravation attraction is zero, the different part of the Earth attract each to hold together.
in the centre of earth, high pressure is resulted by the compression of the mass.