Abstract: Magnus effect describes that，the difference of fluid velocity in the vicinity caused by the rotation of objects in viscous fluid,leads to a transverse Magnus force.It is in the vertical direction of plane composed of angular velocity vector and translational velocity vector.Magnus force is an important factor to influence the trajectory of projectile,and it is often the reason for forming various “curve ball” in ball games.Taking football and table tennis as examples,this paper analyzes their forces,numerically solves their motion equations,compares the trajectory and motion characteristics of small balls under different angular velocities.It systematically studies the influence of Magnus force produced by different angular velocities on the trajectory of small balls,and analyzes the physical principles of several skilled movements in football and table tennis.

Key words: Magnus effect, Magnus force, curve ball