Deep holes v.gravity/air pressure
- Thread starter fly
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If you are halfway to the center, and the density everywhere is the same (actually, matter gets compressed towards the middle) then only 1/8 of the Earth mass is pulling you, but at half the distance, the pull is 4 times stronger ("inverse squares law"), so the final result is 1/2 of the gravity on the surface. At 1/N times the radius, the pull of gravity is just 1/N the pull at the surface.
As you get deeper and deeper, the inside sphere gets smaller and its pull is weaker, so gravity too weakens. At the center, it is zero. At 3 meters from the center, it is the pull of a 3-meter sphere of rock, experienced on its surface--the pull of a tiny asteroid.
http://www.phy6.org/stargaze/StarFAQ2.htm#q29
As you get deeper and deeper, the inside sphere gets smaller and its pull is weaker, so gravity too weakens. At the center, it is zero. At 3 meters from the center, it is the pull of a 3-meter sphere of rock, experienced on its surface--the pull of a tiny asteroid.
http://www.phy6.org/stargaze/StarFAQ2.htm#q29
Syrup Beaver
pants log
Well the reason air pressure is greater in the Dead Sea has to do with larger amounts of air pressing down on that point than at sea level, which is exactly how water pressure works - example being that at 33ft down the pressure is twice what it is on the surface.zengirl said:
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If we pretend that Earth is simply made of rock and that a tunnel all the way through it exists, a ball dropped down the hole would eventually come back. This is due to the nature of the gravitational forces between the ball and Earth.
When the ball is dropped, the force of gravity pulls it down into the hole. As the ball falls farther toward the center of the Earth, the gravitational pull of Earth on the ball becomes less and less. This is because gravitational force due to all of the mass of Earth - which is farther away from the center of Earth than the ball is - cancels itself out and only the mass closer to the center produces a gravitational force on the ball.
Eventually when the ball reaches Earth’s center, all of Earth’s mass is farther from the center than the ball is and the force due to gravity is zero. The ball, however, is still moving vary fast and begins to move away from the center of the Earth.
As it moves away from the center, the mass closer to the center than the ball increases as does the force due to gravity. This force is now trying to pull the ball back toward the center.
When the ball is dropped, the force of gravity pulls it down into the hole. As the ball falls farther toward the center of the Earth, the gravitational pull of Earth on the ball becomes less and less. This is because gravitational force due to all of the mass of Earth - which is farther away from the center of Earth than the ball is - cancels itself out and only the mass closer to the center produces a gravitational force on the ball.
Eventually when the ball reaches Earth’s center, all of Earth’s mass is farther from the center than the ball is and the force due to gravity is zero. The ball, however, is still moving vary fast and begins to move away from the center of the Earth.
As it moves away from the center, the mass closer to the center than the ball increases as does the force due to gravity. This force is now trying to pull the ball back toward the center.
Air pressure at sea level is the equivalent of having many blankets, which would feel very heavy. If you have only one blanket though, it would feel very light, and this is like the air pressure at the top of a mountain. Each layer of air presses down on the layers below, and so the greatest pressure is at ground level where we have the maximum amount of air above. If we go above the height of mountains and into the stratosphere, the pressure will decrease until it reaches about zero, as here there is hardly any air above it.
http://www.rcn27.dial.pipex.com/cloudsrus/pressure.html
http://www.rcn27.dial.pipex.com/cloudsrus/pressure.html
Coqui said:Which didn't answer the question at all
"Eventually when the ball reaches Earth’s center, all of Earth’s mass is farther from the center than the ball is and the force due to gravity is zero."
Okay, so what you're saying is that the closer to the core one goes, the less pull of gravity there is... right?b_sinning said:
What the others are saying is that the closer to the core one goes, the greater the air pressure.
What sort of effect do these two elements have when they're combined? I know I sound dumb, but this is interesting to me, I like hearing what you all think.
That is exactly the quandry. Which is greater, the increase in air pressure or the decrease in gravity?zengirl said:
Syrup Beaver
pants log
Coqui said:
At 1/N times the radius, the pull of gravity is just 1/N the pull at the surface.
So gravity is 1/n-500miles which would be less than the surface.
http://volcano.und.nodak.edu/vwdocs/vwlessons/lessons/Earths_layers/Earths_layers9.html
Inner Core
The inner core of the Earth has temperatures and pressures so great that the metals are squeezed together and are not able to move about like a liquid, but are forced to vibrate in place as a solid. The inner core begins about 4000 miles beneath the crust and is about 800 miles thick. The temperatures may reach 9000 dgrees F. and the pressures are 45,000,000 pounds per square inch. This is 3,000,000 times the air pressure on you at sea level!!!
Gravity drops as you approach the center but the pressure from the crust pushing everything towards the center increases. This would also apply to air.
Syrup Beaver
pants log
If you drop it in deep water (Assuming it's capable of sinking) it wouldCoqui said:Damn I was hoping it would shrivel up instead
ChikkenNoodul said:If you drop it in deep water (Assuming it's capable of sinking) it would
What if it's dehydrated