1. Video: Top Gear

2. P2 – Forces and Motion
Lesson 7: Speeding

3. Lesson Objectives
To be able to describe the factors that affect stopping distances.
To be able to calculate thinking distances.
To be able to calculate braking distances.

4. Does speed matter? http://www.youtube.com/watch?v=Ctkqd6hYMy8
To be able to describe the factors that affect stopping distances.
To be able to calculate thinking distances.
To be able to calculate braking distances.
Keywords: Thinking Distance, Stopping Distance, Braking Distance.
Does speed matter?

5. What affects the time it takes you to stop?
To be able to describe the factors that affect stopping distances.
To be able to calculate thinking distances.
To be able to calculate braking distances.
Keywords: Thinking Distance, Stopping Distance, Braking Distance.
What affects the time it takes you to stop?

6. What is involved with braking?
To be able to describe the factors that affect stopping distances.
To be able to calculate thinking distances.
To be able to calculate braking distances.
Keywords: Thinking Distance, Stopping Distance, Braking Distance.
What is involved with braking?
Spot the hazard.
Thinking Distance – the time taken between seeing the hazard and hitting the brakes.
Braking Distance – the time taken between applying the brakes and the car stopping.

7. Thinking Distance This can be affected by:
To be able to describe the factors that affect stopping distances.
To be able to calculate thinking distances.
To be able to calculate braking distances.
Keywords: Thinking Distance, Stopping Distance, Braking Distance.
Thinking Distance
This can be affected by:
How fast you are going – the faster you are travelling, the further you will travel.
How dopey you are – this can be as a result of being tired, under the influence of drugs, old age and/or careless attitude.

8. Braking Distance This can be affected by:
To be able to describe the factors that affect stopping distances.
To be able to calculate thinking distances.
To be able to calculate braking distances.
Keywords: Thinking Distance, Stopping Distance, Braking Distance.
Braking Distance
This can be affected by:
How fast you are travelling – the faster you travel, the further it takes to stop.
How heavily loaded you are – with the same brakes a heavily laden vehicle takes longer to stop.
How good your brakes are – you must keep them well maintained.
How good the grip is – this depends on the road surface, weather conditions and tyres.

9. To be able to describe the factors that affect stopping distances.
To be able to calculate thinking distances.
To be able to calculate braking distances.
Keywords: Thinking Distance, Stopping Distance, Braking Distance.
Other factors
Don’t forget that you stopping distance can also be affected by:
Bad visibility – fog, bright oncoming lights, heavy rain, snow etc.
Distractions from passengers, mobile phones, music, etc.

10. Stopping Distances – the combined thinking and braking distance.
To be able to describe the factors that affect stopping distances.
To be able to calculate thinking distances.
To be able to calculate braking distances.
Keywords: Thinking Distance, Stopping Distance, Braking Distance.
Stopping Distances – the combined thinking and braking distance.
Speed (mph)
Thinking Distance (m)
Braking Distance (m)
Stopping Distance (m) 20 6 12 30 9 14 23 40 24 36 50 15 38 53 60 18 55 73 70 21 75 96

12. Stopping a car. Thinking distance Braking distance Wet roads
Which of phrases below affect ‘Thinking distance’, and which affect ‘Braking’ distance’? Match them up.
Wet roads
Tyres/brakes worn out
Poor visibility
Tiredness
Too many drugs
Icy roads
Too much alcohol
Driving too fast

13. Stopping a car. Thinking distance Braking distance Tiredness
Too much alcohol
Too many drugs
Driving too fast
Braking distance
Wet roads
Poor visibility
Tyres/brakes worn out
Icy roads
Which of phrases below affect ‘Thinking distance’, and which affect ‘Braking’ distance’? Match them up.

14. Where else can this be used:

15. To be able to describe the factors that affect stopping distances.
To be able to calculate thinking distances.
To be able to calculate braking distances.
Keywords: Thinking Distance, Stopping Distance, Braking Distance.
Test Reactions
Use a stopwatch to start and stop you stopwatch as soon as possible. Record you times.
Repeat trying to get your stop watch to stop on 1 minute, then 2 and 3 minutes.
Think about:
How can you make your data as reliable as possible
What conclusions can you draw?

16. Are you now able to….
To be able to describe the factors that affect stopping distances.
To be able to calculate thinking distances.
To be able to calculate braking distances.
Keywords: Thinking Distance, Stopping Distance, Braking Distance.
I still feel unsure. I need some more help to understand.
I feel ok. I need to do some more work to check my understanding.
I am happy and feel I understand and can explain the main points.