6.4 Braking and collisions

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• Middelbare school
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• Leerjaar 2

6.4 Braking and collisions

In traffic you always have to able to stop in time without having a collision.

If you drive to fast, you might miss a curve.

If the initial speed is high, de braking distance is long. 

The greater the mass of the vehicle, the longer the breaking distance.

If the road is slippery you have to brake slowly.

If your braking force is to high the car skids.

And sometimes the brakes just fail....

initial speed and braking distance

If the speed is n times greater, 

the breaking distance becomes n² times longer.

v = 10 m/s

s = 5 m

v = 20 m/s

s = 20 m

v = 30 m/s

s = 45 m

n² = 2² = 4

n2 = 32 = 9

What's the STOPPING distance?

stopping distance = reaction distance + braking distance

A horse runs to the finishline at 39.6 km/h. The drivers reaction time is 0.2 s. The braking distance is 22.8 m. Determine the stopping distance.

A horse runs to the finishline at 39.6 km/h. The drivers reaction time is 0.2 s. The braking distance is 22.8 m. Determine the stopping distance.

given: v = 39.6 km/h = 11 m/s (39.6 / 3.6)

            t = 0.2 s

           s1 = 22.8m

asked: stopping distance

Solution : reaction distance : 

                   s2 = v x t = 11 x 0.2 = 2.2 m

           Stopping distance : s1 + s2 = 22.8 + 2.2 = 25m

A horse runs to the finishline at 39.6 km/h. The drivers reaction time is 0.2 s. The braking distance is 22.8 m. Determine the stopping distance.

given: v = 39.6 km/h = 11 m/s (39.6 / 3.6)
t = 0.2 s
s1 = 22.8m
asked: stopping distance
Solution : reaction distance :
s2 = v x t = 11 x 0.2 = 2.2 m
Stopping distance : s1 + s2 = 22.8 + 2.2 = 25m

Work

Sum 6.4

do 38, 40, 41, 42, 44