Horizontal and Vertical Motion

• Projectile motion


  A form of motion where an object given an initial velocity is thrown or projected and is allowed to be acted on by gravity in a curved-like path
• Projectiles


  Objects thrown
• Trajectory


  Curved path
• Type 1: Horizontally Launched Projectiles

  • Projectiles that are launched with an initial velocity from an elevated position and follows a curved-like path to the ground
• Type 2: Angle-Launched Projectiles


  • Projectiles launched at an angle with respect to the horizontal and rises to a peak while moving horizontally. Upon reaching the peak, the projectile falls with a motion that is symmetrical to its path upwards to the peak
• Projectile motion examples


  • A volleyball being served
  • A baseball hit by a bat
  • A flight of a soccer ball
  • Slice serving of the Ping-Pong ball
  • Smashing of shuttlecock
  • 100m dash
  • A motorbike taking off on a ramp
  • Dragonboat paddling race
  • Car racing
  • Short course swimming
• Parabola


  Curved pattern
• The rider as it takes off a cliff is the projectile in situation A
• The golf ball as it flies into the air and returns back to the ground is the projectile in situation B
• As the rider takes off from the cliff

  Its downward vertical velocity is increasing due to the presence of gravity which accelerates the rider at 9.8m/s interval downward
• As the golf ball rises in the air

  Its vertical velocity decreases
• When the golf ball reaches the maximum height
• When the golf ball returns to the ground

  Its vertical velocity will decrease
• Type I: Horizontally Launched Projectiles

  1. The vertical velocity of the marble is gradually increasing from points A to D

  2. There is no external net force acting along the horizontal direction (ax = 0)
• Type II: Angle-Launched Projectiles

  1. Horizontal velocity (vx) is still constant

  2. As the projectile ascends (point A to B) the upward, vertical velocity (vy) is decreasing

  3. As the projectile reaches the maximum height (point B) it momentarily stops causing a vertical velocity equal to zero (vy = 0)

  4. When the projectile descends (point B to C), vertical velocity is increasing
• As the projectile reaches its highest peak, the vertical velocity continuously increases
• In angle-launched projectile, as the projectile rises its vertical velocity decreases
• The acceleration due to gravity is not equal to zero