Question

Find the distance in kilometers between the following pair of cities, assuming they lie on the same north-south line. The radius of the Earth is approximately 6400 km. City A at 20° N, and City B at 31° S (round your answer to the nearest km)

Answer 1

5,697 km

Step-by-step explanation:

The distance along the north-south line (longitude) is a distance along a great circle.

Given City A at 20°N, and City B at 31°S:

Step 1: Find the angular difference:

Note that since they are on a different axis, we add:

`\begin{gathered} \theta=20\degree+31\degree \\ \theta=51\degree \end{gathered}`

Step 2: Find the distance:

The distance in kilometers between cities A and B is 5,697km (to the nearest km)​.