QR4 M1

• Projectile


  An object that is given an initial velocity and is then acted solely upon by gravitational force

  
• 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

  
• Projectile motion


  • The object is given an initial velocity
  • The object is then acted solely upon by gravitational force
  • The object follows a curved-like path called a trajectory

  
• Trajectory


  The curved path followed by a projectile

  
• In projectile motion, the physical principles and mathematical formulas that must be applied are those concepts that were recalled earlier</b>
• Horizontally launched projectiles


  1. Initial horizontal velocity

  2. Constant horizontal velocity

  3. Vertical motion under gravity

  
• The horizontal motion of a horizontally launched projectile is independent of its vertical motion

  
• Projectiles launched at an angle


  1. Initial velocity at an angle

  2. Horizontal and vertical components of velocity

  3. Parabolic trajectory

  
• The horizontal and vertical motions of a projectile launched at an angle are not independent

  
• The maximum height of a projectile launched at an angle is reached when the vertical velocity is zero
• The range of a projectile launched at an angle is the horizontal distance it travels from the launch point to where it hits the ground
• As the player kicks the rattan ball, you observed the motion of the rattan ball
• What will be your observations as you look into the motion of the ball on a strobe? Is it situation A or situation B? What do you think would be the explanation?
• Projectile


  Objects that move in projectile motion
• In projectile motion, the physical principles and mathematical formulas that must be applied are those concepts that were recalled earlier. Combining the two allows us to make predictions concerning projectile motion.

  
• Horizontally launched projectiles


  Projectiles that are launched with an initial velocity from an elevated position and follows a curved-like path to the ground

  
• Gravity is the natural force that causes objects to fall towards the earth. Hence, the acceleration due to gravity is always directed downwards and has a value of -9.8m/s2.
• 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.

  
• Parabola


  The pattern of an angle-launched projectile's trajectory motion

  
• Projectile motion


  Consists of horizontal and vertical motion working independently

  
• As the player kicked the rattan ball in the air, the ball will eventually go back to the ground still due to gravity as it moves horizontally.
• Illustrate the trajectory of the ball in order for Sam to get a goal. Explain how you came up with that trajectory.
• Help Mat shoot his crumpled paper right at the trash can by illustrating the trajectory. Explain how you ended up with that trajectory.
• Sports/games that exhibit projectile motion


  • Volleyball
  • Shuttle cock
  • Baseball hit by a bat
  • Soccer ball
  • Dragonboat paddling race
• Sports/games that do not exhibit projectile motion


  • Motorbike
  • Car racing
  • 100m dash
  • Swimming
  • Pingpong ball slice serving
• Achieving projectile motion in sports


  1. Jumping

  2. Throwing

  3. Kicking

  4. Hitting
• The vertical velocity (vy) of the golf ball as it rises in the air decreases
• When the golf ball reaches the maximum height, its vertical velocity becomes zero
• When the golf ball returns to the ground, its vertical velocity decreases
• The horizontal velocity (vx) of a horizontally launched projectile is constant

  
• In an angle-launched projectile, as the projectile rises, its vertical velocity decreases
• When an angle-launched projectile reaches its maximum height, its vertical velocity becomes zero
• The horizontal acceleration (ax) of a projectile is zero
• The acceleration due to gravity is -9.8m/s2
• As a projectile approaches the ground, its vertical velocity increases

  
• There is no external force acting on the horizontal motion of a projectile

  
• Motion diagrams of the types of projectile motion


  1. Height

  2. Range

  3. Vertical velocity

  4. Horizontal velocity

  5. Angle

  
• The horizontal velocity (vx) in horizontally launched projectiles is always constant
• In angle-launched projectile, the vertical velocity (vy) decreases as the projectile rises
• In angle-launched projectile, the projectile's vertical velocity becomes zero at its maximum height