Water traveling along a straight portion of a river normally flows fastest in the middle, and the speed slows to almost zero at the banks. consider a long straight stretch of river flowing north, with parallel banks 40 m apart. if the maximum water speed is 3 m/s, we can use a quadratic function as a basic model for the rate of water flow x units from the west bank: f(x) = 3 400 x(40 − x). (a) a boat proceeds at a constant speed of 5 m/s from a point a on the west bank while maintaining a heading perpendicular to the bank. how far down the river on the opposite bank will the boat touch shore?