Question

Peshawar in Pakistan and Columbia in SC, USA are at the same latitude `54^o N`. Their longitudes are `71.7^o E and 81.1^o W`. The radius of the Earth at this latitude is nearly 6371 km. How do you find the latitude-circle distance between the two cities?

Answer 1

`9987 km`, nearly.

Explanation:

The radius of the latitude circle of latitude `theta^o` is

(Radius of the Earth at latitude `theta) X cos theta`.

Here, this is `6371 X cos 54^o`= 3744.8 km, nearly.

The latitude-circle arcual distance between two places of longitudes

differing by `beta` is

(Latitude circle radius) X (longitude difference `beta` in radian).

Here, it is

`3744.8 X( (71.7+81.1)/180) X pi` km

`= 9987 km`