How does gravity change when going to the center of Earth?

[sidra]

gravity question

the force of gravity decreases as we go away from the serface of the earth...but wt happens when we go inside the crust towards the center of the earth...most say that the gravity decreases....but i say it should not decrease....wt do you think...thin the mass of the earth is still same ...try to answer...

 

[flatulent]

Re: gravity question

Gravity follows Gauss' law of electrostatics for the electric field at any point inside a spherical volume of uniform charge. The gravity declins as you go down the path to the center of the earth.

One way to think of this is that the material above you pulls up and that below pulls down.

 

[ehsanelahimirza]

Re: gravity question

hi

gravity decreases when going down to earth bcz our distance from center is decreased.it doesnt depend upon mass of earth. it will depend upon that part only which is now between our point and the center of earth.

it is not a decreasing thing everywhere.
it also depends upon specific gravity of the earth cores where gravity is to b measured

 

[DrDolittle]

Re: gravity question

This is analogous to walking into a cave and weighing more as we are getting closer to the center of the earth. But it's not so.

We need to remember that gravity is the attraction of mass for other mass, so that when we're in a cave the mass of the rocks ABOVE us is pulling UP on us. So that even if we're closer to the center of mass of the earth, gravity will not go up much. If you are at the center of the earth, gravity is zero because all the mass around you is pulling "up" (every direction there is up!).

Regards
drdolittle

 

[sidra]

Re: gravity question

well one of my friend said that gravity doesnot depend upon mass..then wt about the basic formula
Fg=Gm1m2/r²

and y the gravitational force of the moon is less than the gravitational force of the earth......well when u r going inside the crust through 1km..then u can consider the mass on yr upper side to be a hollwo ball whose surface is 1km thick....but the ball is still pulling u inside...why?....because the ball will attract u towards its center....and the center of the ball on yr upper side is stii the same...ie.the center of the earth...plz think...and try to understaund wt in saying...

 

[neils_arm_strong]

gravity question

gravity depends on the mass of the objects.This mass is that which is coverd up o the distance at which other body is placed.That is it is more like a gaussian volume.
So as we go deeper the gravity decreases.

 

[janath]

Re: gravity question

When you go inside the sphere we should only consider the mass inside the point you specifies. Other mass outside the point doe not matter. So as you go inside mass


would be K*r^3 and force will be K*R^3/R^2=KR.... that is why it reduces.....


Remember faraday cage..... There is no gravitational effect due to out side mass

 

[jimjim2k]

gravity question

Hi

This is my (jimjim2k) lemma:

The gravity declines in the sephere untill we reach the edge of FE-Liquid Core (usually called Magma).


jimjim2k

 

[iftikhar3]

gravity question

hi
it is directly propotional to mass
and inversely propotion to distance
so when we go inside the earth the force of gravity decreases