1. The problem statement, all variables and given/known data At major league baseball games it is commonplace to flash on the scoreboard a speed for each pitch. This speed is determined with a radar gun aimed by an operator positioned behind home plate. The gun uses the Doppler shift of microwaves reflected from the baseball, as we will study in a later chapter. The gun determines the speed at some particular point on the baseball's path, depending on when the operator pulls the trigger. Because the ball is subject to a drag force due to air, it slows as it travels 18.44 m toward the plate. Use the equation below to find how much its speed decreases. V=V0e-kx Suppose the ball, with a mass of 0.145 kg and cross-sectional area of 4.20 10-3 m2, leaves the pitcher's hand at 98.0 mi/h = 43.8 m/s. Ignoring its vertical motion, determine the speed of the pitch when it crosses the plate. (Assume a drag coefficient, D, of 0.305 and a resistive force, R, of 1.2 N.) 3. The attempt at a solution How do i know what the k stands for in V=V0e-kx? so i assume it is the drag coefficient, D, of 0.305 43.8e(-0.305x18.44) = 0.158m/s the answer looks very wrong, and it is wrong indeed. but how do i know what is the k in the equation stands for? or perhaps i shouldn't just sub in the value like that? may i know what is the proper way of doing this kind of question?