As you saw in the video, gravity causes the falling man to gain speed as he travels toward the center of Earth. The acceleration caused by gravity on Earth is about 9.8 meters per second (m/s) per second. That means that every second, the speed of a falling object increases by 9.8 m/s.

The man keeps moving toward the other end of the tunnel. However, once he passes the center of Earth, gravity continues to pull him toward the center, which is now in the opposite direction from how he is moving. As a result, gravity causes the man to slow down as he moves from the center toward the other end of the tunnel.

In two to four sentences, describe how gravity affects the speed at which the man falls through the tunnel.