posted by Alison .
A swimmer wants to cross a river, from point A to point B, as shown in the figure. The distance d1 (from A to C) is 200 m, the distance d2 (from C to B) is 132 m, and the speed of the current in the river is 1.0 m/s. Suppose that the swimmer's velocity relative to the water makes an angle of 60 degrees with the line from A to C, as indicated in the figure. To swim directly from A to B, what speed, relative to the water, should the swimmer have?