Question

A bird is flying 30 mph in a direction 30 degrees south of east. Affecting the flight of the bird is a wind blowing from the northeast to the southwest at a speed of 10 mph. What is the resulting speed of the bird?

Answer 1

draw the vector triangle (head to tail).

I have on my sketch 30 at 30deg SofE, and then on its head a vector of 10 pointing SW. The angle (check this) between the two vectors is (30+45) degrees

Law of cosines>
R^2=10^2+30^2 - 2*10*30*cos75
solve for the resultant R

Answer 2

26