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 to calculate speed and velocity?


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?


55 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