1.2 Motion

• Average speed = total distance / total time
• Speed & Velocity


  Rate of change of distance = How fast the object moves
• Unit of velocity is m/s (metres per second)
• Equation of Speed or Velocity: Speed or Velocity = Distance or Displacement / Time taken to travel a distance

  
• The average speed of an object travelling along a straight line with changing velocity can be found by dividing the total distance covered by the total time taken, or by finding the area under the graph of displacement against time.
• Acceleration is defined as the rate of change of velocity.
• If there are no forces acting on an object, its acceleration will be zero.
• If there are no forces acting on an object, it will continue moving at constant velocity until acted upon by another force.
• Distance-Time Graph: A distance-time graph shows how far an object has travelled during a certain amount of time.
• Velocity-Time Graph: A velocity-time graph shows how fast an object is moving over a period of time.
• Displacement-Time Graph: A displacement-time graph shows where an object is located relative to a starting point over a period of time.
• Speedometer: A device that measures the speed of a vehicle.
• Acceleration


  Rate of change of velocity = how fast an object is speeding up or down
• Equation for Acceleration: Velocity (m/s)² = Change in Velocity (m/s²) / Time (s)

  
• Free Fall: When an object falls freely under gravity, it accelerates at a constant rate of 9.8 m/s² on Earth's surface.