How Magnus Bends the Flying Ball – Experimenting and Modeling

Abstract

Students are well aware of the effect of the deflection of sports balls when they have been given a spin. A volleyball, tennis, or table tennis ball served with topspin results in an additional downward force that makes the ball difficult to catch and return. In soccer, the effect of sidespin causes the ball to curve unexpectedly sideways, resulting in a so-called banana kick that can confuse the goalkeeper. These surprising effects attract students’ attention such that the motion of sports balls can be used to capture the interest of students towards the physics behind it. However, to study and analyze the motion of a real ball kicked in a playfield is not an easy task. Instead of the large-scale full-size sports ball motion, there can be designed and studied simpler experiments that can be carried out in the classroom. Moreover, digital technologies that are available at schools enable students to collect data from the experiment easily in a reasonable time. The mathematical model based on the analysis of forces acting on the ball flying in the air can be used to simulate the motion in order to understand the basic physical principles of the motion so that the best correspondence may be found.

Analysis of the Movement Track of Top Spinning Ball and Biomechanics in the Process of Hitting Tennis Ball

“…When a tennis ball moves in the air, assuming that it does not rotate, it shall move parallel and forward. After receiving a rotating force, the ball will produce a Magnus effect [18] to deflect its motion track. It is because the surrounding fluid also rotates in the process of rotation, and the flow velocity becomes larger on one side and smaller on the other side, forming a lateral force to change the flight direction of the object.…”

Resources for sports engineering education

“…Goff explains the basic physics before summarising recent work across a range of sports. Other papers that lend themselves well to teaching cover the physics of ski jumping [51], baseball trajectory modelling [52], magnus force [53] and golf ball drag [54]. Cross [54] showcases a simple experiment to measure the drag on a golf ball by dropping it into a water tank.…”

A study of football goal trajectories of trained players through a kinetic model

“…However, the above training method relies heavily on the coaches’ teaching level and the players’ understanding ability, leading to a low adjustment efficiency for the shooting technique. In order to adjust and optimize the shooting technique more efficiently [5], physical analysis is introduced into the training process. The scientific analysis of the football flight trajectory enables coaches and athletes to analyze their shooting level deficiencies more objectively and set a clear training goal to enhance the efficiency of shooting training [6].…”