1. The problem statement, all variables and given/known data A boat can travel a speed vB in still water. The boat needs to cross a river of width D from point A to point B on the opposite side directly across. On this particular day, the river's current has a speed of vR. Answer the following in terms of D, vB, and vR. For parts (a) and (b), the boat attempts crossing by pointing itself perpendicular to the river's current as shown. (a) What is the angle θ? (b) What is the component of the boat's velocity that is parallel to the dotted path?