motion

• • distance is how far an object oves
  • distance is a scalar quantity so it does not involve direction
• • displacement is a vector quantity
  • it measures distance and direction of straight line from object's start to finishing point
• • speed is a scalar quantity
  • it does not involve direction
  • speed is how fast you are going
  • speed can affected by age, terrain, fitness
  • typical speeds:
  • walking - 1.5 m/s
  • running - 3 m/s
  • cycling - 6 m/s
  • car - 25 m/s
  • train - 30 m/s
  • plane- 250m/s
• • speed of sound in air is 330 m/s
• • velocity is speed in a given direction
  • velocity is a vector quantity
  • objects travel at constant speed with changing velocity
  • this happens when an object changes direction whilst staying at same speed
  • an object travelling in a circle at constant speed has constant changing velocity as direction is always changing
• • acceleration is how quickly you are speeding up
  • acceleration is change in velocity in amount of time
  • constant acceleration is uniform acceleration
• terminal velocity:

  • friction acts in opposite direction to movement
  • drag is resistance in a fluid
  • streamlining object reduces drag
  • frictional forces increase with speed
  • when falling object first starts, force of gravity is more than frictional force
  • so it accelerates
  • speed increases so friction increases
  • reduces acceleration until equal with frictional force
  • will have reached terminal velocity