69. Suppose the object in Problem 68 had an initial velocity in the horizontal direction equal to the terminal speed, vx0=mg/b. Show that the horizontal distance it can go is limited to xmax=mvx0/b, and find an expression for its trajectory (y as a function of x ).
68. Moving through a liquid, an object of mass m experiences a resistive drag force proportional to its velocity, Fdrag =−bv, where b is a constant. (a) Find an expression for the object's speed as a function of time, when it starts from rest and falls vertically through the liquid. (b) Show that it reaches a terminal velocity mg/b