An instrumented car approaches a fixed hazard marker. Its first coloured track is reaction distance; the second is braking distance. Change speed, reaction time, deceleration and grade to see whether it stops before the marker.
• 3D scene parts: Braking vehicle; grade-adjustable test road; reaction distance strip; braking distance strip; hazard marker. • Controls: Initial speed (20–120 km/h); Perception–reaction time (0.5–3.5 s); Level-road braking deceleration (1.5–7 m/s²); Uphill-positive grade (-8–8 %); Hazard distance (30–220 m). • Live readouts: Reaction travel (m); Braking travel (m); Total stopping distance (m); Current speed (km/h); Distance travelled (m); Hazard clearance (m). • Guided experiments: Wet-road proxy; Long reaction; Downhill. • Four tabs (visual laboratory, curves and measurements, experiments, learn and assess), a model-verification run, a timestamped event log and a trial report.
u=V/3.6; aeff=a+9.81G dreaction=u tr; dbrake=u²/(2aeff) dstop=dreaction+dbrake Positive G is uphill; grade uses the small-angle approximation
Constant deceleration point-mass model, no ABS, tyre-slip, collision or injury model. The car may pass the hazard marker if clearance is negative. Road length rescales to fit the full stop; visual body size and slope are exaggerated. Try the preset experiments, then compare the live readouts with the equations.
No: it quadruples it. At fixed deceleration, braking distance scales with speed squared.
Yes. Gravity adds to deceleration for positive grade.
Constant deceleration point-mass model, no ABS, tyre-slip, collision or injury model. The car may pass the hazard marker if clearance is negative. Road length rescales to fit the full stop; visual body size and slope are exaggerated.