A dolphin wants to swim directly back to its home bay, which is 0.85 km due west. It can swim at a speed of 4.35 m/s relative to the water, but a uniform water current flows with speed 2.82 m/s in the southeast direction.

(a) What direction should the dolphin head???

(b) How long does it take the dolphin to swim the 0.85-km distance home???