if you have a hole straight through the Earth and drop a ball what would happen?

Question

i believe the center of the Earth would have to be Zero gravity,the ball would travel to the center if you dropped it in the other side as well..Think about it.

Answer 1

You're right that the ball would feel no gravity at the center of the earth. So its gravitational potential energy at that point would be zero.

But when it arrived at the center of the earth, it would be moving very, very fast. That is, its kinetic energy would be very large.

The ball would fly past the center of the earth and start slowing down as its kinetic energy was converted back to gravitational potential energy. Note that according to an observer on the other side of the planet, the ball is now flying upward, out of the hole.

Once the ball reached the top of the hole on the other side of the earth, it would slow down and reverse direction, just like if you throw a ball straight up.

If there were no air in the hole, the ball would feel no resistance and it would continue going back and forth forever. But because air is there to slow the ball down, it would eventually stop at the center, after going back and forth many, many times.

Answer 2

The real answers:
You can't dig a hole that big, the center of the earth is liquid.
The ball would burn from the heat.

But assuming you want the more fun answers, let's assume you could place a tube through the earth that would support an empty passage, and then you controlled the heat:

Then the ball would fall towards the center, but would constantly be slowed down by air resistance. AT the center, it would no longer be pulled by gravity, but it WOULD still be moving quite fast. It would pass the center at a high rate of speed, and continue towards the other side, but it would not make it to the surface before being slowed by gravity and pulled the other way back towards the center. It would swing back and forth across the center in shrinking amplitudes until it fell to resting at the center. At that point, there would be no gravity acting on the ball, except a small wiggle caused by stuff like the earth's oscilation and the moon's pull.

Now, for more fun, assume away the resistance of air:

The ball would travel from one side of the surface of the planet to the other, then back, and back, basically forever. Much like a pendulum swings on a large clock. It would accelerate towards the center, reach maximum velocity at the center, then decelerate until it reached the opposite surface at 0 Km/h (Mph), and then fall back again.

Answer 3

Assuming an invincible ball, it would bounce around as it fell faster and faster until the force with which it hits the wall will counter the force of gravity and the ball would reach a terminal velocity for air resitance and this force. I have no idea how fast it would be, but i'll take an educated guess at around less than 300 miles an hour. So the ball would fall down down down the hole and pass the center point. from here, it would bounce around on the walls and slow down. The force of downward gravity is counteracted as the ball falls, and as such, it lessens until it becomes zero or very close. if we assume friction, the ball would take eons to reach the center. If we assumed the ball wouldn't hit walls and it had an infinite density, it would reach the exact height on the opposite side. All your bases are belongs to friction.

Answer 4

If we take away the extreme pressure and heat that increases as you near the Earth's core, there would be a negative point where the ball would slow and stop.
In a perfect experiment, which is impossible, the forces of gravity would cancel each other and you would have a big fat zero. Given the Earth has a core of molten nickel, I'm glad this is just a fun thought/question.

Answer 5

okay i am thinking about it....... and have come to a conclusion..If the center is with out gravity than the ball will plummit through until it gets just before the center at which time it will gravitate onto the portion of the earth that has gravity. I imagine like magnets going a certain course, once close enough they gravitate towards the other that is pulling them. However, I always thought that the center was very hot. I think in this case the ball would plummit to the center at which point it would explode or melt once reaching the center. Maybe this deserves at least one thums-up at least i tried:)

Answer 6

It would zoom down and accelerate until it got to the center, at which point it would start decelerating (since it would be going up) until it gets to the surface of the other side, then it would fall back down, and the cycle would repeat itself. This assumes that the earth is a perfect sphere and that the hole is evacuated of all air so there is no wind resistance to slow it down. Each cycle from end to end of the earth would take slightly over 42 minutes. Check out the article on 'gravity trains' on Damn Interesting (damninteresting.com).

Answer 7

If a tunnel is made along the diameter passing through the centre and drop a ball in it, it will pass through the centre and reach the other end of the tunnel with zero velocity and then turn back. It will execute simple harmonic motion between the two ends of the tunnel.It is assumed that the density of the earth is uniform throughout.

Answer 8

The ball would melt due to the extreme core temperature.

If by some magic the ball didn't melt.. it would have a cool orbit pattern around the center of the earth forever.

Answer 9

it would end up stuck at the core of the earth because that is where all gravity from this planet pulls to

Answer 10

It will fall to the center and stay there.