A rowboat crosses a river with a velocity of 3.37 mi/h at an angle 62.5° north of west relative to the water. The river is 0.590 mi wide and carries an eastward current of 1.25 mi/h. How far upstream is the boat when it reaches the opposite shore?
V = 3.37mi/h[180o-62.5o] + 1.25mi/h[0o]
V = X + Yi
V = (3.37cos117.5+1.25)+i3.37sin117.5
V = (-1.56+1.25) + 2.99i
V = -.306 + 2.99i = 3.0mi/h[95.84o]
tan(95.84-90) = d/0.59
d = 0.59*tan(5.84) = 0.0603 mi=319 Ft.