Journey through the center of the earth
Congratulations! You just dug a tunnel to the opposite end of the Earth. To celebrate, you drop a rock straight down into the hole. If the tunnel passes directly through the center of the Earth, then what will happen to the rock after you drop it?
- There is no air resistance and the ball is thrown straight toward the center of the Earth.
- The Earth is a perfect sphere, the interior is a uniform solid, the rock is electrically neutral, and the tunnel is drilled along the axis of rotation of the Earth's spin.