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    I've got a Physics assignment but I'm not 100% sure exactly what it is asking of me. Our Physics teacher gave it to us in a hurry during a Chemistry lesson so was hardly thorough, he barely said anything! I'm on an Access course btw. It says:

    Write a short illustrated report of approx 800 words on The Physics used in Traffic Accident Investigation
    Give examples of the way in which measurements at the scene of an accident can provide evidence for a subsequent police report.
    Suggested topics for your report:-
    How to calculate distance from speed and deceleration
    How friction can be used to calculate deceleration
    How the values of friction between tyres and road can be determined experimentally
    Possible factors that might influence friction
    How the path of a projectile can be an indication of the speed of a vehicle
    Worked examples of how the speed of a vehicle can be determined from a given set of measurements

    You can use material provided as a basis for your report.

    So far I've written this:
    The Physics used in Traffic Accident Investigation
    The use of physics in a traffic accident investigation is essential. Most important is the accuracy of measurements for the police report, which can provide crucial evidence to support or oppose a criminal case. This is why using physics accurately to provide the relevant authorities with the necessary information is vital as it could be the difference between an innocent man being wrongfully imprisoned and a guilty man being allowed to walk free.When a car’s brakes are applied very sharply the wheel stopsrolling and spins or slides on the surface of the road and produces a skidmark, which are often easily visible on the road. These marks can be used toestimate the distance a car travelled from when the brakes were applied to thefinal position of the vehicle.
    Calculating distance from speed and deceleration
    In order to calculate the distance when given the speed and deceleration of a vehicle we must use the formula Vf2=Vi2+2ad where Vf=Final velocity, Vi=Initial velocity, A=Acceleration and D=Distance.Let Vf = 0m/s, Vi = 50m/s, A= -4.0m/s2 (Deceleration= Negative Acceleration) and D = 312.5mWhen we put the above figures into the formula we produce:02=502+2(-4)(312.5)50*50=25002*(-4)=-8-8*312.5 = -25000=2500-2500Thus, the calculation has been proved correct. However, we knew the distance value before we calculated the equation. What if we didn’t knowthe distance and wanted to calculate it using just the initial velocity, finalvelocity and deceleration? We would change the subject of the formula.Vf2=Vi2+2ad can be rearranged so d=(Vi2-Vf2)/2aIf we input the same figures into the new equation, it willproduce the same answer.312.5=(502-02)/2*(-4)312.5=2500/(-8)In conclusion, we can calculate the distance a vehicletravelled using just the speed (initial and final) and the deceleration.

    What do you think? It's only 300 words.
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    You forgot to include the fact that a car which crashes really fast needs special relativity applying to it.
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    (Original post by TunaTunnel)
    You forgot to include the fact that a car which crashes really fast needs special relativity applying to it.
    Thank I'll look into that, I've had four physics lessons so getting to grips with it all at the moment.
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    (Original post by TunaTunnel)
    You forgot to include the fact that a car which crashes really fast needs special relativity applying to it.
    erm? Explain?
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    I'm confused too
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    bump
 
 
 
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