if you drill a hole in the U.S. ,through the center of the earth, to the other side to, lets say china. and then someone in the U.S. jumped in the hole and was falling and reached the center of the earth. does he keeping falling until he flies out of the hole on the china side or does gravity reverse and he starts going back towards U.S. Basically its a question about gravity. i hope you understand what i mean. a little bit hard to explain it while typing. i asked my brother and he knew what i meant so it shouldnt be too hard. its a hypothetical question. i know you cant drill through center of earth. well atleast with todays technology.
2007-01-14 06:19:05 · 9 answers · asked by cparkmi331 3 in Science & Mathematics ➔ Physics
also, when he reaches center of earth, would he just float there and be stuck between 2 forces of gravity pushing opposite ways?
2007-01-14 06:20:10 · update #1
everyone saying that they would stop in center of earth. wouldnt they be stuck there because of two opposing forces of gravity pinning him in the center?
2007-01-14 06:43:55 · update #2
When the person jumps into the hole on the U.S side, they will accelerate down towards the center of the Earth, in the direction of China. As they fall, they are continually accelerating and their velocity always changing. As they get closer to the center of the Earth, the rate of acceleration slows...but their speed continues to increase.
As the person reaches the center of the Earth, the gravitational force the person feels goes to zero...they stop accelerating. At this point, the person has reached their maximum speed. But just because they are no longer accelerating does not mean that they are not moving...they have build up quite a bit of momentum as they fell, so they will continue traveling through the hole.
As the person passes the center of the Earth and are moving towards, they would begin accelerating again towards the center of the Earth (but moving away from the center of the Earth). Now the gravitational force acts to accelerate them towards the U.S and away from China. They would continue to accelerate in the opposite direction of motion until they got all the way to China. They would eventually pop out of the hole at the opposite side of the Earth and get up to their original height above the hole.
Then they would begin to fall again and the process would repeat.
They would fall down towards China, accelerate always towards the center of the Earth, and pop out on the other side, only to fall back down again. They would begin to oscillate back and forth through the Earth, forever.
All of this assumes that there is no friction. Once you introduce friction (air resistance) into this system, then the person begins to slow down and the process will not continue forever. Eventually, their oscillations would slow down and the person would come to a stop in the center of the Earth.
EDIT:
There are not, "two opposing forces of gravity pinning him in the center". At any given time, there is a maximum of one net gravitational pull...and this will always be towards the Earth's center of mass. When the person is located at the Earth's center, there will be no net gravitational pull...the person will feel weightless, they will not be "pinned" anywhere.
2007-01-14 06:31:45 · answer #1 · answered by mrjeffy321 7 · 1⤊ 1⤋
To your additional info: "also, when he reaches center of earth, would he just float there and be stuck between 2 forces of gravity pushing opposite ways?
3 hours ago
everyone saying that they would stop in center of earth. wouldnt they be stuck there because of two opposing forces of gravity pinning him in the center?"
No. Gravity acts as an attraction to the center of the earth. If you want to be get into technical details: The person has a minute attraction to each tiny partical making up the earth. The net vector sum of all (a nearly infinite number) these attractions is a force directed to the center.
2007-01-14 10:07:56 · answer #2 · answered by sojsail 7 · 0⤊ 1⤋
Standard question from Gauss' Law for gravity!
The force acting on a body with mass m on a distance r from the center of a spherically symetric body with mass M and radius R is
F = G M m r / R^3 for r
This is like elastic force
F = k r,
with k = G M m / R^3
so, the motion will be harmonic oscillations with a period
T = 2*Pi*Sqrt(m/k) = 2*Pi*R*Sqrt(R/GMm)
Note that this is the same as the period for orbiting the Earth with the first cosmic speed. This is to be expected from Kepler's Laws as the linear motion is an elipse with the small semiaxis equal to zero and the large semiaxis equal to R. We know that two trajectories with the large semiaxes equal have equal periods of revolution.
2007-01-14 06:33:17 · answer #3 · answered by Bushido The WaY of DA WaRRiOr 2 · 0⤊ 1⤋
OK.
The center of mass is at the center of the earth. So, you would fall through accelerating to the center and decelerating out to the other side. Due to friction from air, you wouldn't quite make it before you would reach zero velocity just short of the surface, and fall back through the center to the other side, ping-ponging back and forth, a little shorter each trip, until finally you came to rest at the center.
2007-01-14 06:26:07 · answer #4 · answered by Jerry P 6 · 1⤊ 1⤋
OK picture a wheel turning.. the outside diameter spins slower in rpm (revolutions per minute) than the inside(center) so as you fell toward the center of the earth , centrifugal force would eventually paste you to the wall of the hole and that's were you'd stay. hope this helps
2007-01-14 06:30:12 · answer #5 · answered by Stuka 4 · 0⤊ 1⤋
If you negated the effect of air resistance (which would be significant at the speeds he would reach!) then he would just oscillate about the centre of the earth, with a constant amplitude. In effect, he would keep going between the US and China indefinitely.
If air resistance were taken account of, then the amplitude of his oscillations would decrease each time, so he would eventually end up, after a lot of oscillations, stationary at the centre of the earth, where no force was acting on him.
2007-01-14 06:30:58 · answer #6 · answered by readie252 2 · 1⤊ 1⤋
Would think that when reaching the center that he would be pulled apart by both sides of gravity.
2007-01-14 06:26:54 · answer #7 · answered by Anonymous · 0⤊ 1⤋
yes i can. And you have to understand that there are not "2 opposing forces" of gravity at the centre of the earth, there is ONE single gravitational force PULLING towards the centre.
2007-01-14 06:51:37 · answer #8 · answered by Onyx Blackman 3 · 1⤊ 1⤋
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2016-12-12 11:20:11 · answer #9 · answered by Anonymous · 0⤊ 0⤋