Stopping Distance

Key Stage 4

Meaning

Stopping distance is the distance a vehicle travels between the driver noticing a hazard and coming to a stop.

About Stopping Distance

Stopping distance is made of two parts:

• Thinking Distance - The distance travelled by the vehicle between noticing a hazard and putting the foot on the brakes.
• Braking Distance - The distance travelled once the vehicle has applied the brakes.

Stopping Distance = Thinking Distance + Braking Distance

Stopping distance depends on:

• The speed of the vehicle - The greater the speed the larger the stopping distance.
• Thinking Distance
  • The reaction time of the driver - The longer the reaction time the longer the thinking distance. This is affected by alcohol, drugs and tiredness.
• Braking Distance
  • The conditions of the road and tyres - The less friction between the road and tyres the longer the braking distance and therefore stopping distance.
  • The condition of the brakes, if they are in poor condition there will not be enough friction.
  • The mass of the car. The more mass a car has the more force is required to slow it down (Newton's Second Law) so brakes providing a constant force won't be as effective. Higher: See Inertial Mass.
  • Weather conditions - Ice reduces friction with the road making braking distance longer.

References

AQA

Stopping distance, page 164, GCSE Physics, Hodder, AQA

Stopping distance, pages 141, 166-7, GCSE Physics; Student Book, Collins, AQA

Stopping distance, pages 242, GCSE Combined Science Trilogy 2, Hodder, AQA

Stopping distances, pages 148-149, 157, GCSE Physics; Third Edition, Oxford University Press, AQA

Stopping distances, pages 176-178, GCSE Combined Science Trilogy; Physics, CGP, AQA

Stopping distances, pages 208-210, 212, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA

Stopping distances, pages 215, 216, GCSE Combined Science; The Revision Guide, CGP, AQA

Stopping distances, pages 67, 69, GCSE Physics; The Revision Guide, CGP, AQA

Edexcel

Stopping distances, page 155, GCSE Combined Science; The Revision Guide, CGP, Edexcel

Stopping distances, page 22, GCSE Physics; The Revision Guide, CGP, Edexcel

Stopping distances, pages 26-27, GCSE Physics, Pearson Edexcel

Stopping distances, pages 49-52, GCSE Physics, CGP, Edexcel

Stopping distances; estimating, page 51, GCSE Physics, CGP, Edexcel

Stopping distances; factors affecting, pages 49, 50, GCSE Physics, CGP, Edexcel

Stopping distances; typical values, page 52, GCSE Physics, CGP, Edexcel

OCR

Stopping distance, pages 220-221, Gateway GCSE Physics, Oxford, OCR

Stopping distances, page 210, Gateway GCSE Combined Science; The Revision Guide, CGP, OCR

Stopping distances, pages 90, 91, Gateway GCSE Physics; The Revision Guide, CGP, OCR