Braking Distance
Braking Distance
The distance to stop grows with the square of speed — the reason small speed increases sharply lengthen braking distances.
The braking distance is s = v²/(2·a). where v is the initial speed and a the deceleration.
Inputs
v := 25 m/s=25 m/s
a := 7 m/s^2=7 m/s^2
Convert kinetic motion to stopping distance.
s := v^2/(2·a)=44.64 m
Results
At 25 m/s the car needs about 45 m to stop. Doubling the speed quadruples the distance — plus the driver’s reaction distance on top.
Assumptions & limitations
- Constant deceleration.
- No reaction-time distance included.
- Straight-line stop.