Stopping distance sim
Stopping distance = thinking distance + braking distance.
Stopping distance · covers the GCSE, IGCSE, O-Level topic
What the sim shows
Stopping distance = thinking distance + braking distance. While the driver reacts, the car keeps its speed: thinking distance = speed × reaction time, the rectangle under the velocity-time graph. Then the brakes slow it steadily (7 m/s² on a dry road, 5 m/s² on a wet one): braking distance = speed² ÷ (2 × deceleration), the triangle. Twice the speed means twice the thinking distance but four times the braking distance. Tiredness, alcohol and phones lengthen the reaction time; wet or icy roads and worn tyres lengthen the braking distance.
- Light: thinking distance, at full speed
- Dark: braking distance, slowing to a stop
Use it in your lessons
- Try it here: anyone can unlock 2 figures free, and a free account unlocks up to 5. Runs on a laptop, a Chromebook or a phone; nothing to install.
- Present it and share student links with the teacher plan, from US$5 a month, billed yearly.
- Put it on your own website or LMS for US$9, paid once, or every sim from US$29 a month.
Free guide: 12 practicals as sims, and how to run one in a lesson →
Need a version for your exact set-up? Have one made: US$49 a figure in an order of 5.
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