Forces acting on car during collision: Why a car leaves the road on a bend, Factors affecting overall stopping distance, Airbag Physics, Seatbelt Physics, Recent Car Safety

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1. Stopping distance is the distance traveled from the moment a driver first registers danger, to when the vehicle comes to rest. Describe significant factors which can affect your overall stopping distance and how this can be reduced.

Two components which directly affects overall stopping distance is: Reaction time and braking distance, both can be reduced to see a decline in stopping distance.

Reaction time

Reaction time is when the driver becomes aware of a hazardous situation; a period of time must elapse before the driver takes corrective action towards it. There are various factors affecting reaction which basically includes the human physiological system which involves the brain, nervous system and muscle system.

Major factors affecting reaction time are:

* Urgency - drivers generally brake faster when there is a great urgency to, therefore causing the car to skid, where the force applied by the locked brakes is greater then force of friction.

* Driver's attention (state) - Reaction time of the driver may be heavily influenced and reduced, while under the influence of alcohol where the driver's sense and perception sensors are slightly blocked and therefore causing a longer span of time for him/her to react. Another substantial component is other driving/non driving matters take part in the driver's attention and hence increase the reaction time.

* Response capability - humans have highly complex sensory and perception sensors which identify possible dangers and allow the body react in an effective manner in order to avoid the danger, however while in motion of collision, drivers usually steer in the opposite direction of motion to balance out the left and right sliding forces. However while on heavily traffic congested roads; the driver may approach oncoming traffic.

Braking Distance

Braking distance is the distance required for a vehicle moving at a speed to come to a complete stop once brakes have been activated. There are many significant factors which affect the overall stopping distance which are:

* Speed of vehicle before brakes being applied

* Braking distance is proportional to the square of the speed, which therefore means that there will be a significant increase of speed will see a dramatic increase of braking distance.

* Traction of tyres

* The depth of tyre treading is an important factor which contributes to the overall stopping distance, where a decrease in tyre treading proportionally affects the performance of the vehicle's potential braking distance

* State of break pads - when brake disc and brake pads come into contact, the concept of friction applies which slows down the car, where kinetic energy is transferred into other forms of energy such as heat/ sound. Worn down break pads work less efficiently as there is a lesser friction applied to the break downs therefore increasing the time of deceleration.

* Mass of vehicle - in order for a vehicle to stop, Work done by the breaks and friction from the road must balance out the kinetic energy of the car, therefore Newton's second and third law applies, whereas for every reaction, there's an equal and opposite reaction, with relation to the equation Force = mass x acceleration, there has to be a negative force in order to balance out. As mass increases, so does the force needed to "react" in order to slow the vehicle down.

* Road condition

* The slope/ grade of the roadway is a factor within the road as an inclining road, braking distance is greatly reduced due to gravity acting upon the vehicle.

* The frictional resistance provided by the road is another important factor as a car with superior traction on a dry road is less likely to skid, and therefore in turn the braking distance will be reduced compared to a vehicle with less superior traction on a wet/icy road

There are many ways to reduce overall stopping distance through:

- Act responsibly

Keeping to the blood alcohol limit...
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