Distance, Speed and Acceleration

• What is speed a measure of?

  How fast something is travelling
• What type of quantity is speed?

  Scalar quantity
• What type of quantity is velocity?

  Vector quantity
• How can velocity be expressed in terms of direction?

  It can be positive or negative
• What is the formula for calculating velocity?

  v = d / t
• What does 'd' represent in the velocity formula?

  Displacement in meters
• What happens to displacement if an object returns to its starting point?

  Displacement is zero
• What is the relationship between distance travelled and displacement?

  Distance can be non-zero while displacement is zero
• What does acceleration measure?

  Change in velocity per second
• What is the formula for calculating acceleration?

  a = (v - u) / t
• What does 'a' represent in the acceleration formula?

  Acceleration in m/s²
• What does a distance-time graph show?

  Time on the x-axis and distance on the y-axis
• What does the gradient of a distance-time graph represent?

  Velocity

  
• What does a negative gradient on a distance-time graph indicate?

  The object is returning to the starting point
• What does a horizontal line on a distance-time graph indicate?

  The object is stationary
• What does a curved line on a distance-time graph indicate?

  The velocity is changing

  
• What do velocity-time graphs show?

  Time on the x-axis and velocity on the y-axis

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

  Acceleration

  
• What does a negative gradient on a velocity-time graph indicate?

  The object is decelerating

  
• What does a horizontal line on a velocity-time graph indicate?

  The object is moving at constant speed

  
• How can average acceleration be calculated from a curved region on a graph?

  By drawing a straight line through the curve
• How can distance travelled be found on a velocity-time graph?

  By calculating the area under the curve
• What are the two components of stopping distances?

  Thinking distance and braking distance

  
• What affects thinking distance?

  Speed of the car and reaction time
• What factors can slow a driver's reaction time?

  Tiredness, poor concentration, drugs/alcohol
• What factors affect braking distance?

  Speed, road conditions, car condition, weight
• How is overall stopping distance calculated?

  Sum of thinking distance and braking distance
• What happens during hard braking?

  Large deceleration occurs
• How do seatbelts reduce force experienced by passengers?

  They stretch slightly under large forces
• What do crumple zones do during a crash?

  Absorb energy and increase stopping time
• How do airbags protect passengers during a crash?

  Inflate to slow down the head's movement
• What principle do safety features like seatbelts and airbags use?

  Newton’s 2nd Law
• What does the formula F = ma represent?

  Force equals mass times acceleration
• What does 'F' represent in the formula F = ma?

  Force in Newtons
• What does 'm' represent in the formula F = ma?

  Mass in kilograms
• What does 'a' represent in the formula F = ma?

  Acceleration in m/s²
• What does 'v' represent in the formula F = ma?

  Final velocity in m/s
• What does 'u' represent in the formula F = ma?

  Initial velocity in m/s
• What does 't' represent in the formula F = ma?

  Time in seconds
• What other units may be used in the formulas?

  Various units depending on context