Overview

Projectile motion refers to the curved path that an object follows when it is thrown, kicked, or struck through the air. It is a key concept in sport and biomechanics, helping us understand and predict how objects and even the human body move through space under the influence of gravity. Once an object is in motion and no longer in contact with a surface, it becomes a projectile, influenced only by gravity and air resistance.

The path a projectile takes is called a trajectory, and it is shaped by three key factors:

Angle of release – the direction in which the object is launched

Speed of release – how fast the object is moving when it leaves the performer’s hand, foot, or equipment

Height of release – the height from which the object begins its flight

The angle of release determines how high and how far the projectile will travel. For maximum horizontal distance, an angle of approximately 45 degrees is often ideal when release and landing heights are equal. However, in many sports, the optimal angle may vary due to differences in height of release, flight conditions, or specific tactical requirements.

The speed of release has the most significant impact on the distance a projectile travels. A higher velocity means the object will stay in the air longer and cover more ground. Athletes focus on generating as much speed as possible during the release phase to maximise performance—for example, in javelin throwing, shot put, or football kicking.

The height of release affects the total time the projectile is in the air. A higher release point gives the object more time to travel before hitting the ground, increasing potential distance. This is why taller athletes may have a slight advantage in throwing or jumping events, assuming all other factors are equal.

In projectile motion, there are two components of movement:

Vertical motion, influenced by gravity, which pulls the object downward and affects how high and how long it stays in the air.

Horizontal motion, which remains constant (ignoring air resistance) and determines how far it travels.

Understanding projectile motion is essential in many sports, from tracking the arc of a basketball shot, planning a long jump, or perfecting the angle and spin of a serve in tennis. It also applies to body movement in gymnastics or diving, where athletes themselves become projectiles.

Coaches and athletes use the principles of projectile motion to optimise technique, improve accuracy, and enhance performance across a wide range of activities. By manipulating speed, angle, and height of release, athletes can better control outcomes and make informed decisions during training and competition.