Speed

• Distance


  How far an object moves, does not involve direction
• Displacement


  The distance an object moves in a straight line from the start point to the finish point, includes direction
• Distance


  A scalar quantity, has magnitude but no direction
• Displacement


  A vector quantity, has both magnitude and direction
• Speed


  The distance an object traveled divided by the time taken, a scalar quantity
• Calculating speed


  Distance traveled / Time taken
• The symbols for speed and distance are V and S respectively, so they must not be confused
• Typical speeds


  • Normal walking speed: 1.5 meters/second
  • Running speed: 3 meters/second
  • Cycling speed: 6 meters/second
  • Car on main road: 13 meters/second
  • Fast train: 50 meters/second
  • Cruising aeroplane: 250 meters/second
  • Speed of sound in air: 330 meters/second
• The speed of a moving object is rarely constant, but average speed is calculated for a journey
• Calculating distance traveled at constant speed

  Distance = Speed x Time