Velocity-Time Graphs

• Velocity-time graph

  Graph that shows how an object's velocity changes over time
• Velocity-time graph

  • Velocity on y-axis, time on x-axis
• Finding gradient of curve on velocity-time graph


  1. Change in velocity / change in time

  2. Gives acceleration
• Constant positive gradient on velocity-time graph


  Constant acceleration
• Constant negative gradient on velocity-time graph


  Constant deceleration
• Flat sections on velocity-time graph


  Velocity is constant, no acceleration
• Steeper gradient on velocity-time graph


  Increasing rate of acceleration
• Finding distance travelled from velocity-time graph

  1. Calculate area under curve

  2. Split into triangle and rectangle shapes

  3. Use formulas for area of triangle and rectangle
• Area under velocity-time graph gives distance travelled, even though area is usually in m^2
• Estimating area under curved section of velocity-time graph


  1. Use grid background

  2. Count full squares

  3. Combine partially filled squares to make full squares

  4. Total squares gives estimated distance