Distance-Time and Velocity-Time Graphs

You can show journeys on distance-time graphs

If an object moves in a straight line, its distance travelled can be plotted on a distance-time graph

  • Gradient=speed. This is because speed = distance / time
  • Flat sections are where it’s stationary, it’s stopped
  • Straight uphill sections mean it is travelling at a steady speed
  • Curves represent acceleration or deceleration
  • A steepening curve means it’s speeding up(increasing gradient)
  • A levelling off curve means it’s slowing down
  • If the object is changing speed you can find its speed at a point by finding the gradient of the tangent to the curve at that point

You can also show them on a velocity-time graph

How an object’s velocity changes as it travels can be plotted on a velocity-time graph

  • Gradient = acceleration, since acceleration is change in velocity / time
  • Flat sections represents travelling at a steady speed
  • The steeper the graph, the greater the acceleration or deceleration
  • Uphill sections are acceleration
  • Downhill sections are deceleration
  • A curve means ~~changing~~ acceleration
  • The area under any section of the graph is equal to the distance travelled in that time interval
  • If the section under the graph is irregular, it’s easier to find the area by counting the squares under the line and multiplying the number by the value of one square