Distance and Time

• How would you interpret a distance-time graph?

  description of an objects motion
• What does the gradient of a distance-time graph tell us?

  the speed (velocity) of the object at that point
• What will the gradient of a tangent to a curve tell us?

  the speed at that exact moment during an accelerating section on a graph
• What is thinking distance?

  the distance between the driver spotting a hazard and applying the brakes
• What is breaking distance?

  the distance travelled whilst the brakes are applied until the vehicle stops
• What do the thinking and breaking distance depend on?

  the speed of the vehicle
• What factors affect the thinking distance?

  drug/alcohol use, tiredness, distractions
• What factors affect the braking distance?

  weather conditons, road conditions, tyre and brake conditions
• How would you interpret graphs of stopping distances?

  speed-time or distance-time graphs
• During braking, how is kinetic energy is transferred to thermal (and some sound) energy?

  by frictional forces
• What will happen during braking?

  the temperature of the brakes will increase