If you dig a hole straight through the centre of the Earth and jumped in….?
90857
It depends on where you dig the hole !\nIf you dig it on the north Pole (or south Pole) you would accelerate until wind drag compensates for gravitational forces (around 200 km per hour, approximately 120 miles per hour)\nThe gravitational forces become weaker the more you enter the center of the earth (and vanish at the center) so your speed will decrease to a minimum(some speed might remain, because wind drag increased with speed).\n\nI think that you would get stuck near the center of the earth.\n\nIf you dig a hole on the equater, you will probably notice after an hour or so that the wall of the hole seems to get closer to you.\nThe reason is the rotation of the earth: on the equator, you have a speed of some 40,000 km per day (24,000 miles per day - 1000 miles per hour).\nAt lower heights, the earth will still turn in 24 hours - but the circle is smaller, whence the speed.\nAs a consequence, you are likely to scrape against the wall.\n(and remain stuck in the center of the earth as well).
462383
up and down are directions from a gravitional center.  So, one would be digging down from anywhere on the earth's surface until he got to the earth's gravitational center...then he'd be digging up.
1051472
Ok, say the earth was all solid and there was a tunnel from one side to the other.  \n\nYou would keep accelerating as you moved toward the center of the earth, until you reached a very high speed.  As you passed through your speed would be at a maximum.  Then you would begin to decelerate as you went toward the other side.  Neglecting friction and air resistance, you would have just enough momentum to make it up to the surface on the other side, but you would have to grab on or else you would fall back into the hole and go the other way.  You'd continue oscillating back and forth forever if you neglect friction.  \n\nBut of course in real life you would slow down a little bit each time.  Your motion would be like a kid on a swing set, or a pendulum, a gradually decreasing swinging motion until finally you come to rest in the center.
1053136
You can't get to the center of the earth, but basically - Yes, although there may be an exception if:\n1. the mineral rights were not included in the deed\n2. you have sold the mineral rights
730247
Yes, there is gravity at the center of the earth, but it would exert the same force in all directions at once, resulting in a net acceleration of zero.  Therefore, yes, you would float in the same manner as if you were in outer space.
135033
Probably won't work.  If you assume 10 billion people with an average weight of 150 lbs, the mass of the earth is about 10,000,000,000,000 (10^13) times greater.  If everyone jumped up and down, even on the same side of the Earth, it wouldn't affect the earth's momentum or motion in it's orbit.  The acceleration applied by the mass of people is just too small.  Think of it as being in the 13th decimal place(0.0000000000001), it's essentially unnoticeable.
254474
Dude, the world would end up being a s"hit hole..but it woud be fun ride
21030
Assuming you have a tunnel that goes through the earth, take aside the fact you would survive the temperatures and such at the center, assuming there's no resistance (vacumn like environment), you would fall into the hole... accelerate to terminal velocity...pass the center, and slowly decelerating, until you reach back a speed of 0, where you will be at the other end of the hole, whereapart the whole process would start all over again unless you grasp the edge :)\n\nConsidering that the fact there's air, you'll encounter resistence, meaning you will accelerate to the center, start slowing down, but fall short of reaching the other end, then you will fall to the center again, fall even shorter of your original jumping position, and you'll oscillate back and forth until you indeed get stuck in the center of the earth.
699853
At about the center of the earth you would probably burst into flames do to the magma.if you survived that you would be upside down (relative to the ground)
212531
Finally a way for me to pick up that 7-10 split!  :)\n\nI agree with the basic premise of oscillating assuming a vacuum (since we are assuming no molten core, why not a vacuum as well?).\n\nBut, depending on the direction of the hole in relationship to the rotational axis of the earth, wouldn't the ball start bouncing against the sides of the hole due to the mechanics similar to that of a Foucault Pendulum?
622081
Well, that would be some drilling job. How do you propose to get around all that magma exploding upwards once you puncture the containment of the crust you just drilled through? I suspect you will be creating a nasty little, maybe growing into a large volcano. And somewhere along the line, instead of drilling DOWN into the Earth, won't you be drilling ... UP??
61784
That's an interesting qts. I assume that you wish to invlove pure physics in this qts. Forget all the heat at the core of the earth and also air resistance.\nConsider pure gravitation theory.\n\nIf say the fellow who fell in the hole has mass m\n\nThen force of gravity exerted by the earth is :\n\n  F = GMm/(r*r) ..... Where G - universal gravitation constant\n\n                            M - Mass of the earth\n                            r - distance between earth and body of mass m\n\n          acceleration due to gravity\n            = (1-h/R)g   .... where h is distance of body beneath the earth's surface and g is acceleration due to gravity at the surface of the earth.\n\nSo as the body comes closer to the core of the earth, h tends to R.\nSo the acceleration of the body goes on decreasing very much. So, body may not actually hover, since his velocity will be constant the instant it is at the core.
374485
you wont stop "falling" once you got to the ceter of the earth, but by that time you would have a bunch of speed. gravity woulnd't overcome this speed until you got almost all the way to the other side of earth - the whole way assuming earth is a perfect sphere and there is no air resistance. you would basically be a pendulum going back and forth - a pendulum or a swing stops falling in the middle but keeps going because it still has speed. air resitance would eventually slow you down until you want shorter and shorter distances and wound up in the center of the earth, then you would have to climb out. if you were smart, you would grab onto the wall the first time you reached the other side, and climb out only a short distance.\n\nalso the first guy is wrong and the 4th one is right, gravity decreases when you go into the earth - it is strongest right on the surface.
370280
9 miles, and you get to see all of the tormented souls!\n\nGeologists working somewhere in remote Siberia had drilled a hole some 14.4 kilometers deep (about 9 miles) when the drill bit suddenly began to rotate wildly. A Mr. Azzacov (identified as the project's manager) was quoted as saying they decided that the center of the earth was hollow.\n\nSupposedly, the geologists measured temperatures of over 2,000 degrees in the deep hole. They lowered super sensitive microphones to the bottom of the well, and to their astonishment they heard the sounds of thousands, perhaps millions, of suffering souls screaming.
193718
this would all depend on the angle of the secant, the depth of it, and, of course, the velocity at which you would be traveling upon entering the opening.  In general, you would simply roll till you ran out of momentum.  gravity still pulls to the core.
232026
I assume you are asking about how gravity affects the two bodies--the ball and the earth.\n\nGravity acts between the centers of mass of objects.  The center of mass of a ball, and for practical purposes, this would include the earth, is its center.  (This is different for, say, a boomerang.)\n\nWhen you release the ball, the ball and the earth will be attracted to each others center of gravity.  Since the earth is so much more massive than the ball, the amount the earth moves would not be detectable, so let's assume the earth is stationary.  The ball would fall to the center of the earth under an acceleration of 32 ft/sec^2.  When it reached the center, there would be nothing to stop it, so it would whiz on past.\n\nAfter passing the center of the earth, the ball would still be accelerated 32 ft/sec^2 toward the center, but now, since it is on its way up, the acceleration would be subtracting from its upward momentum.  By the time it reached the surface on the opposite side of the earth, it would be moving slowly.  It would rise above the surface by the same amount as you held it above the surface when you dropped it.  Then, it would stop and repeat it's journey.  This would go on forever in the absence of air.\n\nIf you include the effects of aerodynamic drag, the ball would not rise to the same height from which it was dropped.    It would loose height on each trip down and up the hole until it came to rest in the center of the earth.\n\nOf course all this neglects the fact that it is blazing hot down there and would melt almost anything.  \n\nI don't know how to account for the rotation of the earth.  It seems like it would not matter on the first trip downward, since the earth and the ball are moving in the same direction.  However, once it passed the center, the ball would be rotating in the opposite direction from the earth and would slam into the side of the hole with considerable force.  That would really slow it down.  (At least I think that is what would happen.  It would be better to ask a physicist.)
1043854
This is a cool question.  If you were able to tunnel through the Earth, and fall through, your speed would keep increasing until you reached the graviational center.  At that point, the net gravitational force is zero, because all of the forces cancel.  However, you wouldn't just stop because of your inertia.  You would go right through, but then you would begin to slow down, until you reached the other hole.  Depending on how high you started from the first hole, and lets say you jumped five feet above the hole, you would come to a complete stop five feet above the second hole.  Then you would fall back through and continue that cycle.  (Of course we aren't considering air resistance, which screws everything up! ;0)\n\nGuess how long it would take to make it to the other side of the Earth through that tunnel?  Approximately 42 minutes!  Not a bad way of traveling.\n\nThe other cool thing is, if you were to tunnel from say New York to Berlin, which means the tunnel isn't obviously through the middle of the Earth, it would still take you 42 minutes!