What factors affect the motion of a projectile?

The motion of a projectile is primarily affected by gravity, air resistance, initial velocity, and launch angle.

The first factor that affects the motion of a projectile is gravity. Gravity is a force that pulls objects towards the centre of the Earth. It causes the vertical acceleration of a projectile, making it follow a curved path. Without gravity, a projectile would continue in a straight line. The strength of gravity on Earth is approximately 9.8 m/s², which means that for each second a projectile is in the air, its vertical speed increases by this amount due to gravity.

The second factor is air resistance. This is the frictional force that air exerts on a projectile as it moves through it. The effect of air resistance depends on the size, shape, and speed of the projectile. For example, a small, streamlined projectile will experience less air resistance than a large, flat one. Air resistance acts in the opposite direction to the motion of the projectile, slowing it down and reducing its range.

The third factor is the initial velocity of the projectile. This is the speed and direction at which the projectile is launched. The initial velocity can be split into two components: horizontal and vertical. The horizontal component determines how far the projectile will travel, while the vertical component, combined with gravity, determines how high it will go. The greater the initial velocity, the further and higher the projectile will travel.

The final factor is the launch angle. This is the angle at which the projectile is launched relative to the horizontal. The launch angle affects both the height and distance the projectile will travel. For a given initial velocity, a launch angle of 45 degrees will give the maximum range. However, a higher launch angle will result in a higher peak height, while a lower angle will result in a longer flight time. Understanding these factors can help in predicting and controlling the motion of projectiles.

IGCSE Physics Tutor Summary: The motion of a projectile is influenced by gravity, air resistance, initial speed, and the angle it's launched at. Gravity pulls it down, air resistance slows it, initial speed and direction decide its path, and the launch angle determines its height and distance. Understanding these can help predict how a projectile moves, making it easier to control its flight.