You are piloting a small plane, and you want to reach an airport 450 km due south in 2.0 hours. A wind is blowing from the west at 75 km/h.What heading and airspeed should you choose to reach your destination in time?

Answer 1

Make an angle measured from S counterclockwise to heading (somewhere SE)

the Easterly component has to be 75km/hr
The resultant is S, and the heading is 450

Then TanTheta= 75/desired resultantvelocity

TanTheta= 75/(450/2)
solve for Theta.

Your airspeed should be
SinTheta= 75/desiredairspeed
solve for desired airspeed.