Lesson - 1.2.3

• A distance-time graph shows how the distance of an object moving in a straight line (from a starting position) varies over time :

Constant Speed on a Distance-Time Graph

• Distance-time graphs also show the following information:

  • If the object is moving at a constant speed

  • How large or small the speed is

  
  

• A straight line represents constant speed

• The slope of the straight line represents the magnitude of the speed:

  • A very steep slope means the object is moving at a large speed

  • A shallow slope means the object is moving at a small speed

  • A flat, horizontal line means the object is stationary (not moving)

Changing Speed on a Distance-Time Graph

• Objects might be moving at a changing speed

  • This is represented by a curve

  
  

• In this case, the slope of the line will be changing

  • If the slope is increasing, the speed is increasing (accelerating)

  • If the slope is decreasing, the speed is decreasing (decelerating)

  
  

• The image below shows two different objects moving with changing speeds