What wold happen if i dropped a rock through a hole that went throught the world?Details:What would happen if there was a hollow hole through the world, and we dropped a rock in it? We all know magma that would burn it, but what if there was no magma? It can't just fall "Up" onto the other side.
Answer: If you there was no such thing as air resistance, and both sides of the hole were exactly equal distances from the center of the earth, the rock would fall all the way through, and "up" the other side, where it would reach the surface.
It would then fall back down into the hole, and "up" the original side. The rock would continue to do this yo-yo back and forth for about a bazillion years.
Assuming you have air resistance, the rock would reach terminal velocity (look it up) pretty quickly. The rock would make it to the center of the Earth and start up the other side, but it would not get very far "up" the other side. Since it was only going about 250 mph due to air resistance, the force of gravity sucks it back before it can make it up the other side. The rock will again yo-yo a bit, but each swing will get less and less, and eventually the rock will come to rest in the center of the Earth (all gravity is equal pull in all directions at the center)
Hope this makes sense!