Let's say we have four different heights on a marble roller coaster:  1. At the top: .75 meters 2. After the first drop: .2 meters 3. At the top of the loop: .5 meters 4. Before the jump: .1 meters.  The value for gravity is 9.8 meters / second squared; the mass of the marble is .002 kilograms.  Find the Potential Energy at each point on the track: