Stopping distances/Reaction times Flashcards
What is Stopping Distance?
The DISTANCE the vehicle travels on the road from noticing the hazard to when the brakes are applied and the vehicle halts to a stop is called STOPPING DISTANCE.
Use an word equation to link stopping, thinking and braking distance.
STOPPING DISTANCE= THINKING DISTANCE + BRAKING DISTANCE
What is Thinking Distance?
THINKING DISTANCE is the distance a vehicle has travelled on the road from noticing the hazard to when the brakes are applied.
What does the thinking distance depend on?
1) The speed of a vehicle - The faster you are travelling the further the vehicle would have travelled before you apply the brakes.
2) Reaction time of the driver refers to how fast you respond to the situation.
Reaction time meaning?
How fast you respond to the situation.
What does Reaction time depend on?
1) Tiredness -> Increases reaction time
2) Drugs -> Increases reaction time
3) Alcohol -> Increases reaction time
4) Distraction -> Increases reaction time
How do we measure reaction time?
1) Computer screen and see how quickly the screen changes colour by clicking on the mouse.
2) Use the ruler drop test:
You time how quickly you catch a ruler between the thumb and 1st finger when a ruler is dropped from a fixed height.
What is an ideal reaction time?
0.2 to 0.3 seconds
What is the equation for acceleration?
Acceleration = Change in Velocity
——————————
time
Final velocity ^ 2 = Initial velocity ^ + 2 x acceleration x distance
What is braking?
Friction between the brake pads and wheels.
What is braking distance?
The distance a vehicle has travelled on the road from the instant the brakes are applied to when the vehicle stops.
What does braking distance depend on?
1) SPEED- The faster the speed is the longer the braking distance
2) Weaker(road surface) - rain icy conditions on road
-> a bad surface-> Increases braking distance
3)Conditions of brakes - worn out brakes increases breaking distance
4) Condition of tyres - worn out tyres -> means/less grip/less friction
Equation for kinetic energy?
Ke = 1/2 mv ^ 2
m= mass (kg)
V = Velocity (m/s)
What does a large braking force cause?
The car will decelerate rapidly.
What does the braking force mean if you are travelling at high speed?
It means the braking force will be large.
