Final answer:
The gravitational potential energy of a 75.0-kg sightseer can be calculated using the formula GPE = mgh.
Step-by-step explanation:
The gravitational potential energy relative to the surface of Earth of a 75.0-kg sightseer on Edge Walk can be calculated using the formula GPE = mgh. GPE represents gravitational potential energy, m is the mass of the object (75.0 kg in this case), g is the acceleration due to gravity (approximately 9.8 m/s² on Earth), and h is the height above the reference point (in this case, the surface of Earth).
Therefore, to calculate the gravitational potential energy, you need to know the height of the sightseer above the surface of Earth on Edge Walk. Once you have that height, you can substitute the values into the formula and calculate the gravitational potential energy.