Biomechanics: Projectile Motion

Biomechanics: Projectile Motion

Introduction to Projectile Motion

  • Projectile motion involves objects moving in a curved path under the influence of gravity.
  • The motion of a ball after it has been thrown, kicked or hit is an example of a projectile motion.
  • It is characterised by an initial upward ascent followed by a downward descent.

Key Characteristics of Projectile Motion

  • Vertical velocity: This decreases on the way up until it gets to zero at the highest point, then increases on the way down due to gravity.
  • Horizontal velocity: It remains constant because gravity does not affect the horizontal motion.
  • Resultant velocity: This is the vector sum of vertical and horizontal velocity. The angle of projection alters throughout the flight, maximising at take-off and landing.

Factors Influencing Projectile Motion

  • Angle of Release: If the projection angle, release speed, and height of release are constant, a 45-degree angle will produce the greatest horizontal displacement for projectiles launched from the ground.
  • Speed of Release: The speed at which an object is launched has a major effect on the height and distance it will travel.
  • Height of Release: If release height is different than landing height, the optimal angle of release for maximum distance will not be 45 degrees.

The Effect of Air Resistance on Projectile Motion

  • The effect of air resistance on projectile motion is substantial when an object moves at high speed through the air, its shape and size influences this effect.
  • In most A-level situations, air resistance is assumed to be negligible for simplicity.

Calculations in Projectile Motion

  • Maximum height = (Initial speed^2 * Sin^2 Launch angle) / (2 * g)
  • Time of flight = (2 * Initial speed * Sin Launch angle) / g
  • Range = (Initial speed^2 * Sin (2* Launch angle)) / g

Here, g is acceleration due to gravity.

The Importance of Understanding Projectile Motion

  • Understanding projectile motion is critical for optimum performance in various sports such as football, basketball, and athletics (javelin throw, high jump etc).
  • Altering key factors like angle and speed of release can significantly affect the outcome of a performance by increasing the distance covered by a projectile.

Take the time to reflect on the key components and calculations of projectile motion to fully understand its implications on sports performance.