Originally Posted by boeingairbus1981
2 aircraft are heading in the same direction
the cruising speed of aircraft 1 is 460 knts
the distance between aircraft is 35 nm
the 2nd aircraft passes after 21 minutes
what is the speed of the 2nd aircraft?
First we need to work out their relative speed, then obviously add that to the speed of AC-1 which must be travelling faster to 'overtake' AC-1
So you're looking at (35/21)*60 for your nm/h
= 100
so then it's simply 100 + 460 = AC=2 with Cruise Speed of 560.
The only way the "given answer" of 360 can be correct, is if the question does not say "the 2nd aircraft passes after 21 minutes" but instead "the 2nd aircraft is passed after 21 minutes".
Phil