An airplane with a speed of 485 km/h is traveling with a heading of 83.5°. The wind velocity is 38 km/h in the direction of 191°. Find the ground speed of the airplane.

Question

P.S. How do you solve this problem by only using the law of cosine/sine method?

Answer 1

Draw the velocity vector of the plane
add the vector for the wind
The resultant s is the ground speed.

The angle between the two vectors is 72.5°

s^2 = 485^2 + 38^2 - 2*485*38*cos72.5°