Distance-time Graphs

• What do distance-time graphs tell us and show us?

  Distance-time graphs tell us how far something has travelled in a certain amount of time and different parts of the graphs tell us about different bits of the journey
• What does the gradient of the line of any point on a graph represent?

  the speed of the object at that time (this is because speed=distance/time)
• What does a straight line going up or down on a distance-time graph represent?

  Constant speed
• What does a flat line on a distance-time graph show?

  It shows that an object is stationary (because the gradient is 0 and therefore the speed is also 0)
• What does it mean if the line on a graph is getting steeper or less steep?

  • A steeper line shows acceleration (because the gradient is increasing and so is the speed)
  • A line is getting less steep (going down) then this shows deceleration (because the gradient is decreasing and so is the speed)
• What does a curved line on a distance-time graph mean?

  A curved line means that speed of the object is constantly changing
• How do you work out the speed of a point on a curved line on a distance-time graph?

  • Draw a tangent on the point you are looking at
  • Calculate the gradient of the tangent you have drawn
• On a distance-time graph, on what axis is distance and on what axis is time?

  • Distance = y-axis
  • Time = x-axis