Question 1060630
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find the distance in kilometers between the cities whose latitudes are given. Assume that the cities are on a north-south line 
and that the radius of the earth is 6400 km. City E, 13°N and city F, 73°S
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The distance is  {{{R*alpha}}} = {{{6400*((13+73)/360)*2pi}}} kilometers.


13° + 73° is the measure of the arc between the cities in degrees.


The ratio {{{(13+73)/360}}} shows which part of the entire circle is your arc.


The number {{{((13+73)/360)*2pi}}} is the measure of the arc in radians.


{{{R*alpha}}} is the length of the arc of a circle, where {{{alpha}}} is the arc's measure in radians.