Question: The lowest point in Death Valley is 85 m below sea level. The summit of nearby Mt. Whitney has an elevation of 4420 m.
Part A: What is the change in potential energy of an energetic 91.2kg hiker who makes it from the floor of Death Valley to the top of Mt. Whitney?
Part B: If a frictionless track was constructed from the top of Mt. Whitney to the bottom of Death Valley such that a roller coaster car was allowed to run on the track without air resistance, how fast would the car be moving when it reached the bottom?
Please show each step and the equations you used. Thank you!