1. The problem statement, all variables and given/known data A boat whose speed in still water is 1.70m/s must cross a 260 meter wide river and arrive at a point 110 metres upstream from where it starts. To do so, the pilot must head the boat at a 45 degrees upstream angle. What is the speed of the river's current. 2. Relevant equations According to my lecture, I believe the equation should be sin Theta = Vws/Vbs Vws being the water's current, and Vbs the boat's speed. However, I don't know where the river's width comes in. 3. The attempt at a solution Sin 45 = Vws/1.70 m/s Vws = Sin 45 x 1.70 Vws = 1.20 m/s. Would this be correct? THANKS!