Science week 1 free falling object

• Free-falling objects do not encounter air resistance
• All free-falling objects (on Earth) accelerate downwards at a rate of 9.8 m/s2
• Acceleration due to gravity

  The acceleration for any object moving under the influence of gravity alone, denoted by the symbol g
• The numerical value for the acceleration of gravity is most accurately known as -9.8 m/s2
• Free fall motion


  1. Free-falling objects are acted by gravity (force) alone

  2. According to Newton's Law of Acceleration the object's acceleration follows the direction of the net force, which is downward towards the center of the earth
• Uniformly accelerated motion


  Equations for motion with constant acceleration
• Free fall motion


  Equations for motion with constant acceleration due to gravity (g)
• Free fall is a special case of motion with constant acceleration because acceleration due to gravity is always constant and downward
• The equations for uniformly accelerated motion are applicable to free fall motion except that "a" is replaced by "g"
• Each successive second of the object's fall, the object's speed increases by the same amount: 9.8 m/s
• When an object is thrown up in the air


  The object's velocity decreases as it approaches maximum height, then changes direction and increases as it falls back down
• Acceleration from gravity is always constant and downward, but the direction and magnitude of velocity change
• The mass of the object does not affect its motion when it falls in free fall
• Projectile motion is the motion of an object thrown or projected into the air with a constant initial velocity that follows a curved path
• Trajectory


  The curved path followed by the projectile
• Range


  The maximum horizontal distance that a projectile covers
• Projectile motion is two-dimensional, consisting of horizontal motion and vertical motion which are independent of each other
• The horizontal motion of the projectile is unaffected by the presence of gravity
• Gravity causes the projectile to accelerate vertically at a constant rate of -9.8 m/s2
• Since there is only a vertical force (gravity) acting upon a projectile, it does not accelerate horizontally
• Equations for Horizontal Motion of a horizontally launched Projectile


  • 𝒗𝒊𝒙 = 𝒗𝒇𝒙
  • 𝒅𝒙 = 𝒗𝒊𝒙t
  • Range = 𝒗𝒊𝒙𝑡

  
• Equations for Vertical Motion of the Projectile

  • h= 𝒗𝒊𝒚t +

  ��

  𝟐 g��𝟐

  • 𝒗𝒇𝒚𝟐= 𝒗𝒊𝒚�� + 2gh
  • 𝒗𝒊𝒚𝟐 = 𝒗��𝒚𝟐 – 2gh
  • 𝒗𝒇𝒚= 𝒗���� + gt
  • 𝒗��𝒚 = 𝒗𝒇𝒚 - gt
  • h=

  𝒗𝒇𝒚𝟐−𝒗𝒊𝒚𝟐

  𝟐𝒈

  
• Equations for Horizontal Motion of a horizontally launched Projectile


  1. 𝒗��𝒙 = 𝒗𝒇𝒙

  2. 𝒅𝒙 = 𝒗𝒊𝒙t

  3. Range = 𝒗𝒊𝒙𝑡