13. A physics teacher is on the west side of a lake and wants to swim across and end up at a point directly east from his starting point. He notices that there is a current in the lake and that a leaf floating by him travels 2.2 m [S] in 5.0 s. In calm water, he is able to swim 1.8 m/s. (a) [5 marks] Using a vector diagram, find the direction he has to swim in order to arrive at a point directly east of his initial position. (b) [5 marks] Calculate his velocity relative to the shore. (c) [5 marks] If the lake is 545 m wide, how long will it take him to cross the lake?