Final answer:
The distance between two cities on the same longitude cannot be determined without the latitude coordinates. The Haversine formula requires these coordinates, along with Earth's radius, to calculate the distance accurately.
Step-by-step explanation:
The question asks to find the distance between two cities on Earth that are on the same longitude. To answer this properly, one would need additional information, specifically the latitude coordinates of the two cities, as Earth's curvature must be taken into account for accurate calculations.
Option (a) 'Use the Haversine formula to calculate the distance' is the correct approach, but without knowing the latitudes of the two cities, this formula cannot be applied. The Haversine formula is used to calculate the distance between two points on the Earth's surface given their latitude and longitude pairs. The radius of Earth is a crucial part of this formula. Option (b) 'The distance cannot be determined without additional information' is therefore the most accurate answer from the given choices.
Regarding the radius of Earth, it is approximately 6,371 kilometers, but in this context, it was stated as 4000 miles. This value is pertinent as it forms part of the Haversine formula used to compute distances over the Earth's surface.