If we are to draw the motion of the plane and the wind in a Cartesian plane, we take East and North as the positive x and y-axis, respectively. Also, we have the West and South as the negative x- and y-axis, respectively.
To answer this item, we take the x- and y-components of the speeds.
Airplane:
x-component = (400 mi/hr)(cos 45°) = 282.84 mi/h
y-component = -(400 mi/hr)(sin 45°) = -282.84 mi/h
Wind:
x-component = -(50 mi/hr)(sin 90°) = -50 mi/hr
y-component = 0 mi/hr
Adding up the components:
x-component = 282.84 mi/hr - 50 mi/hr = 232.84 mi/hr
y-component = -282.84 mi/hr
The resultant speed would be,
R = sqrt ((232.84 mi/hr)² + (-282.84 mi/hr)²) = 366.35 mi/h
The direction would be,
tan (∅) = -282.84 mi/hr / 232.84 mi/hr
∅ = 50.53° (south of east)
ANSWER: 366.35 mi/hr, 50.53° South of East
