2. Boat \(A\) is sailing due cast at a constant speed of \(10 \mathrm {~km} \mathrm {~h} ^ { - 1 }\). To an observer on \(A\), the wind appears to be blowing from due south. A second boat \(B\) is sailing due north at a constant speed of \(14 \mathrm {~km} \mathrm {~h} ^ { - 1 }\). To an observer on \(B\), the wind appears to be blowing from the south west. The velocity of the wind relative to the earth is constant and is the same for both boats. Find the velocity of the wind relative to the earth, stating its magnitude and direction.