Suppose you are trying to cross from the South bank to the North bank of a river in your covered wagon. With all your earthly possessions, you are able to move your wagon at a speed of 1.3 m/s with respect to the water. The crossing is normally perfectly safe, but it's been a warm spring and the snow melt is causing the river to swell to 20.0 m wide and to flow quickly at 1.0 m/s to the west. a) In what direction do you need to aim your wagon if you want to cross the river without drifting downstream or upstream? b) In what direction do you need to aim your wagon if you want to cross the river in the shortest amount of time? How long will it take you to cross in this case?