摘要或動機

A projectile refers to any body that is thrown in space and falls under the influence of gravity and the motion of such a body is called projectile motion. In this context we will ignore the effects of air resistance to make calculations easier. Through the usage of trigonometric ratios and vectors it is possible to accurately predict the position of a body after a certain time, the maximum height attained by it and the horizontal distance it covers from the point of projection. Horizontal displacement or range of a projectile is the main index of performance in many cases of projectile motion. If air resistance is negligible, there is no net force in the horizontal direction (ΣF = 0; ax = 0) Through this topic we aim to explain the science behind the performed actions and movements in sports such as Golf, Football, Basketball and Javelin throw. Factors Affecting Distance traveled by a projectile: 1. Relative height of release 2. Speed of Release 3. Angle of release Projectile Motion: Theory v/s reality Theoretically optimal angle is about 45° however taking air resistance into consideration the angle reduces to about 42°. Long jumpers use angles of 17-23°. This is because when traveling at ~10 m/s, there is not enough time to generate a large takeoff angle. The game of Golf is based on the trajectory followed by the golf ball as it moves through the air and in this sport we have addressed issues such as the required club face angle and swing speed for the ball to go in the hole. For instance if we have a ten degree driver it will carry the ball lower than a 60 degree wedge and hence it can be deduced from the above statement that a greater angle of the club face launches the ball at a greater angle. Effects of Air resistance can be very large in case of golf. Therefore, the golf ball has dimples on its surface to negate the effect of air resistance. To depict the application of projectile motion in football, we have shot a video on our school’s football field showing the trajectory followed by a football and have addressed issues like horizontal and vertical velocity required depending on the nature of the kick. In the sport of Basketball we shot a video showing a student shooting a 3 pointer. Furthermore with the help of charts, we have calculated the velocity required for a basketball to go inside the hoop at different angles of projection such as 30, 45 and 60 degree. Finally we have included a question to determine whether a ball hit by Sachin Tendulkar will be a six or not using kinematical equations as well as equations related to projectile motion. Hence by shedding light on this wonderful topic we attempt to reveal how an athlete’s brain functions and through years and years of practice and hardwork he is able to accurately predict distances and achieve his goals.