Uniform Accelerated Motion

• Acceleration: Defined as the rate of change in velocity of a moving object per unit time.
• The change in velocity can be achieved in THREE WAYS:

  
  

  Increasing speed:

  Initial velocity = 0 m/s -> Final velocity = 29 m/s

  
  

  Decreasing speed:

  Final velocity = 29 m/s -> Initial velocity = 0 m/s

  
  

  Constant speed but changing direction:
• Speed is defined as distance traveled divided by time taken to travel that distance.
• Changing direction (accelerating from rest)
• CASES OF ACCELERATION:

  CASE 1: When the velocity and acceleration of an object are on the same positive (x) direction, it speeds up (accelerating)

  +a (a = 2.0 m/s^2) = +V (Vi = 2.0 m/s -> Vf = 4.0 m/s)
• CASES OF ACCELERATION:

  CASE 2: When the velocity and acceleration of an object are opposite towards a positive (x) direction, it slows down (decelerating)

  -a (a = -2.0 m/s^2) = +V (Vi = 4.0 m/s -> Vf = 2.0 m/s)
• CASES OF ACCELERATION:

  CASE 3: When the velocity and acceleration of an object are on the same negative (x) direction, the negative acceleration value only denotes direction, but the object still speeds up (accelerating)

  -a (-a = 2.0 m/s^2) = -V (Vi = -2.0 m/s -> Vf = -4.0 m/s)
• CASES OF ACCELERATION:

  CASE 4: When the velocity and acceleration of an object are opposite the same negative (x) direction, the resulting acceleration is positive in value but still indicates an object slowing down (decelerating)

  +a (a= 2.0 m/s^2) = -V (Vi = -4.0 m/s -> Vf = -2.0 m/s)
• When can we say that an object decelerates?

  We have a deceleration whenever the magnitude of velocity is decreasing (it does not necessarily mean a is negative), and then the velocity and acceleration point in opposite directions.
• UNIFORM ACCELERATED MOTION: It takes place when a body maintains a constant change in a given time interval along a straight line