Projectile Motion

• Projectile

  An object/body released into the air
• Projectile motion

  • Flight path is horizontal + vertical
  • Vertical velocity: Speed + direction on the vertical plane
  • Horizontal velocity: deals with motion in x axis direction that's side to side
• Main three factors influencing projectile motion

  • Angle of release
  • Velocity (speed) of release
  • Height of release
• Angle of release

  • Angle at which object is thrown
  • Optimum angle of release is 45 degrees (varies during sporting activities)
• Velocity (speed) of release

  • How fast object's released
  • Largely determined by muscular force
  • Greater speed of release = greater distance
• Height of release

  • How high projectile is released above ground
  • Increased height of release, ↑ the horizontal displacement
• Gravity

  • ↓ the height of projectile
  • Affects vertical component/velocity
  • 9.81 m/s²
• Air resistance

  • Larger surface area = ↑ air resistance
  • Type of surface - rough fair resistance
  • Speed, mass, as speed ↑ air resistance
  • Lighter you are the greater the influence of air resistance
• Weight

  • Can also influence projectile
  • Force of gravity acting on an object is directly proportional to its mass
  • In absence of air resistance, the mass/weight doesn't affect its free fall speed
• Parabola

  Symmetric shape, a curve with equal left and right sides
• A badminton shot is parabolic
• When reaching the top of the parabola

  Vertical velocity is shown above
• If Angle of Release is optimal (45 degrees)

  The greater the vertical displacement/velocity, the greater the horizontal displacement/velocity
• Aerodynamics

  Lift force and downforce created when air flows over an aerofoil
• Bernoulli Principle

  Explains why aeroplanes fly and why racing cars stick to the ground going around corners
• Aerofoil

  • Air flow travels further over the top of the projectile than the air passing underneath
  • Angle of attack has to be at 45 degrees
  • Airflow has to travel a further distance, therefore travels faster, at a lower pressure velocity of airflow
  • Airflow has to travel a shorter distance, has a slower velocity of airflow, higher pressure of air
• Pressure differential gradient

  Resulting in pressure of air to move from high to low, causing a lift force upward