SCIENCE JOURNAL 2018

This is due to the physical concept of friction. Friction is the force in which opposes one sur- face moving, or trying to move, over another (Kennett, 2014). In terms of vehicles on roads, various environmental factors such as wet weather, loose gravel, mud and oils can reduce the level of friction seen on road surfaces. Al- though vehicle tires are designed to produce suf- ficient traction during unfavourable conditions (Encyclopedia.com, 2018), a level of traction is lost from the reduced friction of the road sur- faces. As a consequence of this, braking dis- tance would increase, resulting in higher colli- sion speeds. Newton’s First Law – Appendix Five – explains how an interaction between an external force and object in motion change its behaviour. This relationship describes friction as an external force in which opposes the object in motion (tires on vehicle). By applying Newton’s first law against friction as an environmental factor, reduced friction results in a decrease in opposing force onto the surface of the tires, thus requiring more distance to exert the same amount of force in which would be seen in fa- vourable conditions (i.e. dry). Technological Factors In response to motor vehicle accidents that can arise from commuting, laws and regulations have changed over time to enforce car safety and injury prevention technologies in all vehi- cles. Through technological developments, car safety has been improved through the imple- mentation of seatbelts, air bags and crumple zones into all vehicles. Although these technolo- gies do not prevent an accident, they prove to prevent serious injuries or death (Iliandes, 2012). Seatbelts aim to slow a passenger’s for- ward motion as evenly as possible in a fraction of a second (Brain, 2017). As collisions induce a braking force acting on the vehicle, seatbelts aim to restrain them with the vehicle (Harris, 2016). This results in passengers braking with the vehicle during a collision. Evidently, any un-

restrained passengers will not experience a brak- ing force until in contact with an undesirable opposing object, most likely a dashboard or road surface. This would result in serious injury or death. In addition, using the concept of ‘impulse of force’, air bags and crumple zones aim to induce similar forces by slowing a person’s forward movement. These technologies illustrate how injury severity can be lessened through extend- ing the time of collision. Impulse of force is the product of the average force and the time it is exerted – it is the amount of change in an ob- jects momentum. The formula for impulse is ex- pressed: Impulse = Force × Time The process of minimising an impact force can be addressed by extending the time of collision. In doing so, an opposing reduction in average impact force is seen (Physik, n.d.). Thus, air bags and crumple zones act to prolong the colli- sion and reduce the force experienced effective- ly and evenly by the passenger, ultimately re- ducing injury severity. Therefore, due to devel- opments in injury prevention technologies, indi- viduals involved in vehicle accidents see in- creased safety. Moreover, improvements to economic benefits would be seen due to improved injury outcomes, lessening cost of treatment, and reducing acci- dent costs in speed related incidents. Conclusion Therefore, the claim ‘every K over is a killer’, is supported by the evidence found through re- search into the question ‘why is speed such a significant factor in our road statistics’. The re- lationship seen in kinetic energy provides rea- soning as to why increased speeds result in fa- talities, and how reaction time and deceleration

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Somerset College Journal of Scientific Issues

Year 10