Question

A boat attempts to cross a 172 m wide river to reach a dock directly on the other side. The boat heads out directly across the river, perpendicular to the bank, with the motor propelling it at 16 m/s across the water, but he river flowing at 5.4 m/s immediately begins pushing it down river. How far down river ( in meters) from the dock does the boat end up when it reaches the opposite shore?