Question 295678
Two planes leave an airport at the same time, one flying due west at 500km/h and the other flying due southeast at 300km/h. What is the distance between the planes two hours later?
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From their starting point, one plane is 1000 km away, the other is 600 km away.
The angle between their paths is 135 degs
s = distance between the planes
{{{s^2 = 1000^2 + 600^2 - 2*1000*600*cos(135)}}}
{{{s^2 = 1360000 + 1200000*sqrt(2)/2}}}
{{{s^2 = 1360000 + 600000sqrt(2)}}}
s =~ 1486.11 km
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PS   "due southeast" is not a valid navigation term.
It's "due east, due north", etc, only the 4 cardinal compass points.