Velocity time graphs

• What type of graph is used to represent journeys in terms of velocity?

  Velocity-time graph
• What does the gradient of a velocity-time graph represent?

  Acceleration
• What do flat sections on a velocity-time graph indicate?

  Travelling at a steady speed
• How does the steepness of a velocity-time graph relate to acceleration?

  Steeper graphs indicate greater acceleration or deceleration
• What do uphill sections on a velocity-time graph represent?

  Acceleration
• What do downhill sections on a velocity-time graph represent?

  Deceleration
• What does a curve on a velocity-time graph indicate?

  Changing accelerations
• What does the area under a velocity-time graph represent?

  Distance travelled
• How can you find the area under an irregular section of a velocity-time graph?

  Count squares and multiply by square value
• How do you calculate acceleration from a velocity-time graph?

  Find the gradient of the line
• What is the first step to calculate the distance travelled in a velocity-time graph?

  Split the area into shapes
• What is the acceleration of a car over the first 10 seconds if the gradient is calculated?

  Gradient of the line between 0 and 10 s
• How do you find the total distance travelled in the first 15 seconds of a journey?

  Add areas of triangle and rectangle
• What are the steps to sketch a velocity-time graph for a journey with different speeds?

  1. Start with steady speed
  2. Show acceleration at a constant rate
  3. End with a different steady speed
• How would you draw a velocity-time graph for a car's journey that includes acceleration and deceleration?

  1. Start from rest
  2. Accelerate to 20 m/s in 10 s
  3. Maintain speed for 20 s
  4. Decelerate uniformly to stop in 4 s
• What is the initial speed of a stationary car before it starts accelerating?

  0 m/s
• How long does the car travel at a speed of 20 m/s?

  20 seconds
• How long does it take for the car to come to a stop after braking?

  4 seconds
• What is the final speed of the car after accelerating?

  20 m/s
• What does a stationary car's velocity-time graph look like at the beginning?

  Horizontal line at 0 m/s
• What happens to the velocity of the car during the acceleration phase?

  It increases to 20 m/s
• What is the significance of the area under the velocity-time graph during the journey?

  It represents the total distance travelled
• How does the velocity-time graph change when the car begins to decelerate?

  The graph slopes downwards