Difference between speed, velocity, displacement, distance

• What are the two terms we will look at in this video?

  Speed and velocity
• What are the two types of quantities mentioned?

  Scalar and vector
• What defines a scalar quantity?

  It only has magnitude
• What defines a vector quantity?

  It has both magnitude and direction
• Is speed a scalar or vector quantity?


  Scalar quantity
• Give an example of speed.

  A person running at four meters per second
• Is velocity a scalar or vector quantity?

  Vector quantity
• Give an example of velocity.

  A person cycling six meters per second east
• Why is it common to confuse speed and velocity?

  They are often used interchangeably
• What is distance classified as?

  Scalar quantity
• Give an example of distance.

  10 meters or 40 miles
• What is displacement classified as?

  Vector quantity
• Give an example of displacement.

  A person running 40 meters east
• What is the difference between distance and displacement?

  • Distance: Scalar, only magnitude
  • Displacement: Vector, magnitude and direction
• How do you calculate the speed of a train crossing a bridge?

  Distance traveled divided by time taken
• What is the speed of a train that crosses a 550-meter bridge in 10 seconds?

  $55 \text{ m/s}$
• What happens if you replace distance with displacement in the speed equation?

  You calculate the velocity instead
• What does the symbol 's' represent in the velocity equation?

  Displacement
• What does the symbol 's' represent in the speed equation?

  Speed
• What does the symbol 'd' represent in the speed equation?

  Distance
• What does the symbol 't' represent in both equations?

  Time
• Why do people often use the velocity equation incorrectly?

  They may not have a direction
• What is a benefit of using velocity?

  You can have a negative velocity
• What do we calculate when objects vary in speed?

  Average speed or average velocity
• What is the average walking speed of a person?

  About 1.5 meters per second
• What is the average running speed of a person?

  Around 3 meters per second
• What is the average cycling speed of a person?

  About 6 meters per second
• What is the average speed of a car on the main road?

  Around 25 meters per second
• What is the average speed of a fast train?

  Around 55 meters per second
• What is the average speed of planes?

  Can exceed 250 meters per second
• What is the speed of sound waves in air?

  330 meters per second
• How does the speed of sound change in different mediums?

  It varies depending on the medium
• What factors can affect wind speed?

  Temperature, pressure, and structures
• What are the average speeds of different activities?

  • Walking: ~1.5 m/s
  • Running: ~3 m/s
  • Cycling: ~6 m/s
  • Car: ~25 m/s
  • Fast train: ~55 m/s
  • Plane: >250 m/s
• What can wind speed vary from on a still day?

  Almost zero meters per second
• How fast can wind speed be on a windy day?

  Faster than a speeding train
• What is the natural movement of air called?

  Wind
• What is the main topic of this video?

  Speed and velocity
• What should you ensure about speed and velocity for exams?

  Be completely sure which is which