A motor boat heads west across a river as a current of 12 km/hr. The speedometer reads a constant of 26 km/hr. What is the resultant velocity of the boat as compared to its original path? And what is the degree?

Answer 1

X = -26 km/h.
Y = -12 km/h(assuming a southbound current.

V^2 = X^2 + Y^2 = (-26)^2 + (-12)^2=820
Vb = 28.64 km/h.

tanAr = Y/X = -12/-26 = 0.46154
Ar = 24.8o. = Reference angle.
A = 180 + Ar = 180 + 24.8 = 204.8o,CCW.
= 24.8o South of West.