A river flows due south at 14 mih In what direction should t

A river flows due south at 1.4 mi/h. In what direction should the swimmer head, at a velocity of 3 mi/h, in order to arrive at a landing point due east of his starting point? (Round your answer to one decimal place.) N______ ° E

Solution

v1 = speed of the river = 1.2 mph
v2 = speed of the swimmer relative to the water = 2 mph
Vr = resultant speed

v2² = v1² + Vr²

2^2 = 1.2^2 +Vr^2

Vr= 1.6 mph

direction : tanA = Vr/V1 =1.6/1.2

A = N53.3E deg