Distance, speed, and acceleration

• What is the formula for speed?

  Speed = Distance ÷ Time
• What is velocity?

  Speed in a given direction.
• What is acceleration?

  The rate of change of velocity.
• What is the formula for acceleration?

  Acceleration = Change in velocity ÷ Time taken
• What does a straight, sloping line on a distance-time graph mean?

  Constant speed.
• What does a curved line on a distance-time graph represent?

  Changing speed (acceleration or deceleration).
• What does a flat line on a distance-time graph mean?

  The object is stationary.
• What does a sloping line on a speed-time graph indicate?

  Acceleration or deceleration.
• What does a flat line on a speed-time graph indicate?

  Constant speed.
• What does the area under a speed-time graph represent?

  Distance travelled.
• What is the gradient of a velocity-time graph equal to?

  Acceleration.
• What does a steeper gradient on a velocity-time graph mean?

  Faster acceleration.
• What are the two parts of a stopping distance?

  Thinking distance and braking distance.
• What factors affect thinking distance?

  Tiredness, alcohol, drugs, distractions.
• What factors affect braking distance?

  Wet/icy roads, worn brakes/tyres, speed, vehicle mass.
• What is the equation for stopping distance?

  Stopping distance = Thinking distance + Braking distance.
• Why are speed limits important?

  They reduce stopping distances and the severity of collisions.
• How do seat belts help in a crash?

  They spread forces and restrain the occupant.
• How do crumple zones improve safety?

  They increase the time over which momentum is reduced, reducing force.
• How is scientific data used in traffic control?

  To create laws, improve safety, and inform vehicle design.
• Thinking distance

  Distance travelled between spotting the hazard and braking
• Braking distance

  Distance travelled while braking
• How is acceleration or deceleration calculated

  By the gradient of the line
• How is distance travelled calculated?

  The area under the graph