Problema Solution
A boat travels 4 km upstream and 4 km back. The time for the round trip is 2 hours. The speed of the stream is 3 km/hr. What is the speed of the boat in still water?
Answer provided by our tutors
Boat velocity component upstream = 16 cos 35 - 3 = 13.1 - 3 = 10.1 kn Boat velocity component across stream = 16 sin 35 = 9.18 kn resultant speed = sqrt(10.1^2+9.18^2) = 13.6 kn tangent of resultant angle to upstream = 9.18/10.1 = .909 so angle to upstream = tan^-1 .909 = 42.3..