Posted by Noah on Monday, December 3, 2012 at 12:46pm.
An airplane flies due south at 185 km/h relative to the air. There is a wind blowing at 68 km/h to the east relative to the ground. What are the plane's speed and direction relative to the ground?

Physics  Henry, Wednesday, December 5, 2012 at 7:48pm
Vp = 185km/h @270o + 68km/h @ 0o.
X = 185*cos270+68*cos(0)=0+68 = 68km/h.
Y = 185*sin270+68*sin(0)=185+0=185km/h
tanAr = Y/X = 185/68 = 2.72059.
Ar = 69.82o = Reference angle.
A = 69.82 + 360 = 290o = Direction.
Vp = X/cosA = 68/cos290=197 m/s=Velocity
of plane. 
Physics  Jessica, Tuesday, February 12, 2013 at 5:06pm
@Henry: Where the heck did you get 270??