抄録
We investigate the maximum projection angle of a ball acting on drag and lift with constant coefficients. The equation of motion for a particle with drag and lift proportional to the speed is derived from that with the quadratic law of drag and lift. The linearized equation provides the second order perturbed solution of the maximum projection angle. Comparing the perturbed solution with numerical ones obtained from the equation with the quadratic drag and lift, the following results are obtained. (1) Both the drag and lift decrease the maximum projection angle. (2) The decrease due to lift is stronger than that due to drag. (3) The maximum projection angle has a concave curve according to drag while it has a convex shape for lift. (4) The second-order formula of drag and lift gives a good approximation to the maximum projection angle.
