Speed, Velocity, Distance and Displacement

• Define speed.

  How fast something is going with no regard to direction
• Define velocity.

  How fast something is going and the direction it is going in
• Define distance.

  How far an object has moved
• Define displacement.

  Measures distance and direction in a straight line, from the object's starting point to the finishing point
• What is the main difference between speed and velocity?

  • Speed is scalar
  • Velocity is vector
• What is the main difference between distance and displacement?

  • Distance is scalar
  • Displacement is vector
• What is the equation for speed?

  Speed = total distance / total time
• What is the equation for velocity?

  Velocity = total displacement / total time
• What does a negative velocity mean?

  The object is going backwards
• Why do we do the total distance or displacement divided by the total time?

  • Because objects rarely travel at a constant speed, they vary across their journey
  • When we use the total we get an average speed or velocity
• What is the typical speed of a person walking?

  1.5 m/s
• What is the typical speed of a person running?



  3 m/s
• What is the typical speed of a person cycling?


  6 m/s
• What is the typical speed of a car?



  25 m/s
• What is the typical speed of a train?

  30 m/s
• What is the typical speed of a plane?

  250 m/s
• What are some things that can affect the speed at which a person travels?

  • Fitness/health
  • Age
  • Distance travelled
  • How much effort they are putting in
  • Terrain (what type of land they are walking on)
• What are some things that can affect the speed at which wind travels?


  • Large buildings nearby
  • Temperature
  • Atmospheric pressure