/sci/ - Science & Math

>Is gravity subject to the inverse square law?
Yes.
>If I tunnel down half the radius of the Earth, roughly what G's will I be experiencing? More or less?
Less, but inside the earth, it should be proportional to the distance from the center i think (so not ~1/r^2 but rather ~r)

Cheers.

Female scientists = BEST SEX EVER!!!!!!!

>>1183254

No data to support that I'm afraid.

>>1183212
>Less, but inside the earth, it should be proportional to the distance from the center i think (so not ~1/r^2 but rather ~r)
Assuming all the mass is a point at the centre of the earth. Since some of the mass is above you the 'downwards' force will decrease a little.

>>1183201
It still obeys the inverse square law. (>>1183212 what you're thinking of is how the force of gravity changes at different heights, not its strength at those heights) It will be one half as strong since there will be 1/8 the mass of the Earth "below" you (simple geometry and noting that the contribution of an inverse square force from being inside a perfect spherical shell is zero) and the distance is 1/2 (which gets squared to 1/4 from the inverse squared law).

>>1183212
>Less, but inside the earth, it should be proportional to the distance from the center

actually, no; according to the shell theorem, you can ignore gravitational effects from outside the shell, so it's still ~1/r^2, but the mass you would be using in the equation would be whatever mass of the earth is still below you, not the total mass of the earth

>>1183264
If you assumed a point mass in the center, the force would fall off as 1/r^2 everywhere.
>>1183273
Huh.. isn't the potential V inside the earth proportional to r^2? Then the force would be dV/dr and thus proportional to r...

>>1183264
No, that's false. The contribution from the stuff "above" you is zero. http://en.wikipedia.org/wiki/Gauss'_law_for_gravity etc.

OP here, I'm outta my league though I appreciate the discussion.

>>1183290
>>1183273 here. Technically, what we're saying is both true, since m acts like r^3 cancelling with r^-2 to give r^1, but it's best to think about gravity as always acting as r^-2 so that you don't have to work case-by-case.

>>1183315
Well okay I can live with this, so let's leave it at that.

>>1183201
you have to calculate the mass of a ball with a radius of the earth's minus the depth you dug down (use the average density of earth). Now you can calculate the gravitational force at that point. The stuff "above" you doesn't contribute to the force.

>>1183260
Compiled data last night. We went through so many latex gloves and petri dishes, but then we had to stop because the lab caught fire and exploded. Who would have thought that semen and vaginal fluids plus a whole lot of KY would ignite phosphorus.....oh.

less gravity
because the matter above you will pull you back and the matter below you is not as much as before
but in every case you're dead hot magma huge pressure makes you flat and fried

now post /sci/babes :)

1. Yes I think so.
2. Not sure but I think it's really high. Maybe 100 or more?

>>1183403
Fun fact: Marie Curie died of complications related to radiation exposure. Her husband Pierre died of complications related to being run over by a carriage.

>>1183391

Me again. I think a lot of you guys are forgetting a few things.

1. First off the Earth's mass isn't uniform. The shit in the middle is quite a bit denser than the stuff elsewhere.

2. That stuff in the middle is a "heavier" element (Iron)

3. That core of Iron is really packed together (really dense)

So there is quite a bit more mass in the center of the Earth compared to other places.

>>1183417

PS. Remember that inverse law? Well you're much closer to that dense core so you're going to experience quite a bit more Gs than you would up top.

>>1183413

Her personal documents are so irradiated that you have to wear protective gear to even examine her *cookbook* to this day.

>>1183424
>PS. Remember that inverse law?
Remember the shell theorem (aka Gauss's law of gravity)?

>>1183430

Remember when I'm not going to argue with you and just prove you wrong?

http://en.wikipedia.org/wiki/File:Earth-G-force.png

>>1183430
>>1183430

>>1183430
>Status Told.