projectile motion

• Projectile


  An object that is "projected" or thrown, which has no capacity for self-propulsion
• Actual forces on a projectile

  • Drag
  • Lift due to spin
  • Weight
  • Wind
• A well-hit golf ball travels farther than ideal theory predicts because of lift due to spin
• Ideal Projectile

  The only force is weight
• An ideal projectile trajectory is a parabola
• For a given launch speed, v0, the max range is at θ = 45
• General Projectile Problem

  Use the two position equations to solve for the remaining two
• Acceleration due to gravity

  Acts downward
• Projectile motion


  • The acceleration due to gravity acts downward
  • The horizontal velocity is constant
  • The vertical velocity is zero at the highest point of the projectile's flight
• Projectile motion


  1. Fired at an angle

  2. Neglecting air resistance

  3. Changing direction at the highest point

  4. Horizontal net force is zero

  5. Horizontal acceleration is zero
• Projectile motion examples


  • Bullet fired at 45° angle
  • Golf ball shot in high arcing shot
  • Soccer ball kicked at 55° angle
• The initial vertical velocity of a horizontally shot ball is zero