Seatbelts :: essays research papers

When travelling at slow speeds in your gondola car the clothing of a seatbelt has little effect of your proboscis when you brake. So why is it grievous to wear your seat belt?A driver or rider travelling in a car is moving at the aforesaid(prenominal) speed as the car. If the car suddenly stops, the body of the rider at heart go forth keep moving forward at the corresponding speed. This demonstrates inertia. The inclining of a moving object to keep moving, or of a stationary object to remain at rest. Basically Newtons first law that a body stationary or moving with constant velocity will want to continue to do so, unless acted on by a force.Lets represent what is happening here. First drive along in your car at 60 km/h on a backstreet with no traffic, past brake gently and slowly. You will nonice that the seat belt doesnt really do much to hold your body. Now do the same again but this time break as quickly and precipitously as you can. Your body will be thrown forwards with slap-up force, and your seatbelt will be literally holding you in place.Now your body was what is commonly referred to as being "thrown forwards", however this is not the case. Your body was actually not slowing down much at all and your velocity relative to the car initially was much greater. The car began to slow down due to disruption and your body in concord with Newtons First law wanted to continue to move at the certain constant velocity. Now if your seat belt was not there to try an opposing force, to your momentum and inertia, by holding you from going forwards, you very in all probability would have been thrown into the dash or steering wheel.Lets look at this mathematically. m= your mass in kilograms for this purposes 70kgV= final velocity 0 m/s U= initial velocity 60 km/h or 16.6 m/s straight lineS= distance taken to stop 42 mt= 3.8a= -4.368 m/s/s Now your momentum at 60km/h is P=MUSo P= 70kg*16.6m/sP=1162 Kg m/sImpulse I=MU/tI=70*16.6/3.8I=305NSo your body will weigh about 610kg when you are breaking hard, a force it is difficult for any person to withstand.Now in the context of a head on accident at almost 60km/hr the force exerted on your body is greatly increased. In the egress of such an accident it will take the car approximately 0.4 seconds to stop.