b. How far away from Helen's cottage will Judy be when she reaches the other side? c. How long will it take Judy to reach the other side? 11. An airplane is travelling N60E with a resultant ground speed of 205 km/ h. The nose of the plane is actually pointing east with an airspeed of 212 km/ h. a. What is the wind direction? b. What is the wind speed? 12. Barbara can swim at 4 km/h in still water. She wishes to swim across a river to a point directly opposite from where she is standing. The river is moving at a rate of 5 km/h. Explain, with the use of a diagram, why this is not possible. PART C 13. Mary leaves a dock, paddling her canoe at 3 m/s. She heads downstream at an angle of 30 to the current, which is owing at 4 m/s. a. How far downstream does Mary travel in 10 s? b. What is the length of time required to cross the river if its width is 150 m