"The river is 50.0 m wide, and flows east at 3 m/s. A boat that can travel on still water at 5 m/s heads in a direction that allows it to cross the river perpendicular to the shore." Based on this wording, this is the diagram that I came up with, though I really am very unsure as to if it is correct or not. http://www.recklesscaution.com/riverboat.jpg I searched online, and all the examples I could find had the problem not indicating that the boat ends up with a perpendicular motion. Did I assume correctly? Or just goof up again?