Question

A sailboat under auxiliary power is proceding on a bearing 25 degrees North of west at 6.25km/h in still water. Then a tail wind blowing 15 km/h in the direction 35 degrees South of west, alters the course of the sailboat.

What is the resultant speed and direction of the sailboat?

Answer 1

the tail wind: 1.5 km/hour or 15 km/hour?

Answer 2

15km/h

Answer 3

ok, my vector isn't to scale then, but the idea is the same...
find the x and y components of each vector
add the x components of one vector to the x components of the other vector
the result is the x component of the sum of the two vectors
add the y components of one vector to the y components of the other vector
the result is the y component of the sum of the two vectors