A 500-gram red ball on an air track is attached to a compressed spring (at x=0 m the spring is unstretched) as shown in the animation (position is given in meters and time is given in...A 500-gram red ball on an air track is attached to a compressed spring (at x=0 m the spring is unstretched) as shown in the animation (position is given in meters and time is given in seconds). A very wealthy individual proposes to dig a hole through the center of Earth and run a train (the small black circle) from one side of Earth to the other, as shown in the animation (position is given in Earth radii and time is given in seconds).
