Near Espelo you are driving 50 km/h on a dry road. A cyclist unexpectedly crosses. About how many metres do you still travel before you start braking?
- About 3 metres, almost all of it is braking distance after that
- About 1 metre, because a reaction second is one metre
- ✓ About 14 metres, more than half of your stopping distance
Correct answer: About 14 metres, more than half of your stopping distance
Explanation
False — you think the reaction distance is negligible. At 50 km/h you travel about 13.75 m during your reaction time, almost as much as the braking distance of 12.50 m
Why learners get this wrong
- Wrong: you think the reaction distance is negligible. At 50 km/h you travel about 13.75 m during your reaction time, almost as much as the braking distance of 12.50 m
- Wrong: you treat the reaction second as a distance. It is a time of about 1 second; the metres you travel in that time follow from ((speed : 2) + 10%) : 2, at 50 km/h about 13.75 m
Topic: The reaction second and the reaction distance
Read the rule: Core: The reaction second and the reaction distance
Sections
- Challenge: The reaction second and the reaction distance
- The model: The reaction second and the reaction distance
- Core: The reaction second and the reaction distance
- Why it matters: The reaction second and the reaction distance
- Active recall: The reaction second and the reaction distance
- Teach back: The reaction second and the reaction distance
- Memory hook: The reaction second and the reaction distance