Consider once again the swimmer in Example 4.7. Assume she can swim at a velocity of 0.30 m/s and the river is 15 m wide. She needs to get across the river as quickly as possible. 

(a) What direction should her velocity vector make relative to the water to get her across in the shortest time? 

(b) What is her overall velocity as measured from the shore? 

(c) What is the direction of her total velocity as seen from the shore? 

(d) How long does it take her to cross the river? 

(e) How far downstream does she end up?