Road Safety Flashcards
What is thinking distance
Distance traveled in the Time it takes a driver to react
What is braking distance
The distance travelled by a car in the time it takes to stop safely
Stopping distance
Distance for reaction + distance to come to a safe stop
Equation for thinking distance
Thinking distance= speed x reaction time
What affects reaction times
Age
Alcohol/drugs
Tiredness
Visibility
Distraction
Skill
What is the equation for braking distance
Braking distance= initial speed ^2 / 2x acceleration
What affects braking distance
Brake conditions
Vehicle mass
Vehicle speed
Road conditions
Vehicle conditions
Gradient of road
Equation for stopping distance
Initial velocity x time + initial velocity ^2 / 2 x acceleration
What is a risk when braking aggressively
Skidding
What system in modern cars prevent skidding
anti-lock brakes (ABS)
How is collision force measured
Acceleration or deceleration
Acceleration/deceleration in collisions is represented in terms of what
g (acceleration due to gravity)
What does 1 g represent
Approximately 10m/s^2 deceleration
Equation for impact force
Impact force (N) = mass of vehicle (Kg) x deceleration (g)
What is impact time
The duration of impact force
The shorter the contact time, ………………….
The greater the impact force
Equation for impact time
Time = 2 displacement /initial + final velocity
What safety features are present on a car for collisions
Vehicle bumpers
Crumple zones
Seat belts
Collapsible steering wheel
Airbags
Why does car have crumple zones,bumpers and airbags
Increases the time it takes for the a person to decelerate reducing the force applied to the person
Why are seatbelts useful in a crash
As the force applied by seatbelt would be far less than that of the collision
It also prevents person being thrown from a vehicle allowing other safety systems to work
