physics
posted by Anonymous on .
A swimmer swims in still water at a speed of 6.83 m/s. He intends to swim directly across a river that has a downstream current of 2.89 m/s.
(a) What must the swimmer's direction be?

V = 6.83m/s @ (90)o + 2.89m/s @ 0o.
X=6.83*cos(90) + 2.89*cos(0)=2.89m/s.
Y=6.83*sin(90) + 2.89*sin(0)=6.83m/s.
tanA = Y/X = 6.83/2.89 = 2.36332
A = 67.1 = 67.1o Below the desired direction. Therefore, the swimmer must head in a direction 67.1o above the desired direction. 
Vsc = Vs + Vc = 6.83i + 2.89
Tan A = 6.83/2.89 = 2.36332
A = 67.1o CCW = 22.9o E. of N.(9067.1).
Direction = 22.9o W. 0f N.