Question

An aeroplane flies from P(lat 45°N, long 17°W) to Q(lat 45°N, long 53°E) . what is the distance covered by the aeroplane? If the time of flight is 6hours, what is the average speed of the aeroplane

Answer 1

If the earth's circumference at the equator is C, then at latitude θ, the circumference is is C cosθ
so the distance traveled is d = (17+53)/360 * C cos45°
and as usual, speed is distance/time