Projectile 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. These objects are called projectiles. They move due to its own inertia (mass). The curved path followed by a projectile is called a trajectory.
• Projectile moves in two dimensions
• Projectile motion


  It is a combination of horizontal motion and vertical motion. A projectile moves horizontally with constant velocity while being accelerated in a curved path -- forming a parabola.
• Horizontal and vertical motions are independent of each other
• Velocity


  Speed in a given direction
• Velocity of an object changes when: the speed changes; the direction changes; or both the speed and direction change
• Vertical Motion


  • Upward motion
  • Downward motion
  • Maximum height
• Upward Motion


  • Initial velocity is maximum
  • Velocity decreases with passing of time
  • Velocity = 0 at maximum height
• Downward Motion

  • Initial velocity is 0
  • Velocity increases with passing of time
  • Velocity is maximum before hitting the ground
• Horizontal Motion

  Constant velocity in linear motion
• In ideal cases, air friction or air resistance and ground friction are neglected, the object will move in a constant velocity in each point in time forever
• An object moves in a constant velocity with the absence of frictional and gravitational forces
• Projectile Motion

  A form of motion where an object (projectile) moves in a parabolic path (trajectory) and the only force acting upon it is gravity.
• Components of Projectiles

  • Horizontal Motion (x-component)
  • Vertical Motion (y-component)
• Horizontal Motion


  Neglect air resistance, constant horizontal velocity (vx), horizontal acceleration is zero (ax = 0), we call the horizontal distance as RANGE (x)
• Vertical Motion


  Force acting upon it is gravity (g = ay = a9), always g = - 9.8 m/s², not constant velocity (vy) ; changes as a function of time, we call the vertical distance as HEIGHT (y)
• Types of Projectile Motion

  • Horizontally launched projectiles
  • Angle-launched projectiles
• Projectiles launched with an initial velocity from an elevated position and follows a curved-like path to the ground, the acceleration due to gravity is always directed downwards ay = - 9.8 m/s² and ax = 0 ; constant vx, downward vy is increasing
• Angle-launched projectiles are projectiles launched with at an angle with respect to the horizontal and rises to a peak while moving horizontally. It also falls the same way it went upwards, vx is still constant while vy can be described in three parts: the projectile ascends, reaches the maximum height, the projectile descends
• Acceleration due to gravity

  Always directed downwards, a_y = -9.8 m/s²; a_x = 0, constant
• Vertical velocity (v_y)


  Increasing downwards
• Types of Projectile Motion

  • Horizontally launched projectiles
  • Angle-launched projectiles
• Angle-launched projectiles


  1. Launched with an angle with respect to the horizontal

  2. Rises to a peak while moving horizontally

  3. Falls the same way it went upwards
• Vertical velocity (v_y)

  Can be described in three parts: ascends, reaches maximum height, descends
• Projectiles have a uniform acceleration, which is the acceleration due to gravity (g)