Motion

• Distance


  The total length that an object travels
• Displacement


  The change in position of an object in a straight line from the starting point to the finishing point
• Scalar quantity


  Only magnitude is important
• Vector quantity


  Direction is important
• Distance is a scalar quantity
• Displacement is a vector quantity
• Calculating distance from home to school

  2 km + 10 km = 12 km
• Displacement from home to school

  8 km EAST
• Calculating distance John and his dog have travelled

  3 km + 4 km + 3 km = 10 km
• Displacement of John and his dog's trip

  0 km (back at starting point)
• Calculating distance run around 400 m race track

  2 laps x 400 m = 800 m
• Displacement after running 2 laps


  0 m (back at starting point)
• Speed


  How quickly an object travels
• Instantaneous speed


  How fast you are travelling at a specific point in time
• Velocity


  The change in displacement of an object after a period of time
• Velocity is a vector quantity
• Acceleration


  The measure of change in velocity
• Acceleration is a vector quantity
• Calculating acceleration of Holden Commodore

  27.78 m/s - 0 m/s / 6.8 s = 4.08 m/s^2
• Constant acceleration


  Acceleration of an object does not change over time
• Non-constant acceleration


  Acceleration of an object changes over time
• Displacement-time graph


  Records the change of position against time
• Velocity-time graph


  Indicates the change of velocity of an object while in motion
• Acceleration-time graph


  Indicates the acceleration of the object over time
• The slope of a displacement-time graph gives the velocity
• The area under a velocity-time graph gives the displacement
• Isaac Newton was an English mathematician, physicist, astronomer and author
• Newton's Laws of Motion describe the main principles behind motion of an object and forces acting on it
• Newton's First Law


  If an object is at rest, or has a constant speed in one direction, then there is no net force acting on it