Basic Mechanism of Throwlike Movement

As an extension of our physical consideration [2], we study the fundamental mechanism of end-point acceleration on the basis of Newtonian mechanics. With simple models of sticks and their equations of motion, we find that inertial force and gravity, which usually acts unintentionally, play important roles in the kinetic link process. In the rest of this abstract we illustrate how inertial force acts on an extended body by a stick model. Consider a thin uniform stick with mass m and length l, which is put in the y-direction. We call one end A and the other end B. Suppose that one moves A linearly in the –x direction with acceleration a. In that sprit second, how B moves? If we introduce the noninertial frame which moves with A (A-frame), this question becomes much easier. In A-frame, “inertial force” ma appears in the +x direction. Then we obtain the equation of motion of rotation,