Forensic Quiz

Dynamo1 said:
Since the cycle hit the door and not the front bumper, that might mean the car had the right of way because it was already into the intersection. There were no skid marks to show the cycle trying to brake at the last moment.
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The cycle was traveling down a road it would seem, and struck a car that was trying to make a left hand turn onto the road (US road).


As far as temperatures and undercarraige goes, you can find any evidence you want, and any temperature you want. Just explain how it will help you reach your conclusion.
 
After the glass has been identified, I believe the next step would be to determine the velocity of the two vehicles using the coefficient of friction.

Also check for characteristic soil--- check to see if the road is unpaved or inadequately paved. I f so , there is a possibility that it may contain very characteristic elements.Spectrographic analysis will be useful.

As for the understructure--Any disturbance in the grease should be noted.
 
Well, then, the only way is take temperature readings of its radiator. If this reading differs gratly from the temperature of the surroundings, it means that it was used recently. The tests should be made to find out that is needed for the water to cool to this temperature after it has been driven ten -fifteen minutes. This time should be compared with the time that has elapsed since the accident.
 
VManso said:
Well, then, the only way is take temperature readings of its radiator. If this reading differs gratly from the temperature of the surroundings, it means that it was used recently. The tests should be made to find out that is needed for the water to cool to this temperature after it has been driven ten -fifteen minutes. This time should be compared with the time that has elapsed since the accident.
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It is a given that both vehicles were being used around the time in question. Assume the water in the radiator of the car can be related back to "normal operation temperature".

Assume the cycle is air cooled.
 
The rate of cooling is proportional to the difference in temperatures. Knowing this, one must keep in mind two laws of cooling : that of Stefan-Boltzmann and that of Newton.
 
So if we coould determine if the headlights were turned on we can tell if the driver was telling the truth about the motorcyle's headlight not being turned on and whether he saw the motorcycle coming.
 
Hrockz said:
So if we coould determine if the headlights were turned on we can tell if the driver was telling the truth about the motorcyle's headlight not being turned on and whether he saw the motorcycle coming.
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This is absolutely true. If the headlamp was on while it collided with the car, and if it was broken, the lamp itself will react in different way to the rapid exposure to oxygen. If this reaction is present, it would be clear the headlamp was on or not.

The second part of this quiz though, is to determine the speed of the oncoming motorcycle. And that can still be determined by the physical evidence left at the scene.
 
There are seven mechanical factors to consider in order to determine how far the car was travelling when the collision happened, the primary one being the speed of the vehicle. The others are whether the road is unpaved or inadequately paved, the condition of said road, whether dry , wet, snowy or icy; the tread design of the tires, the wear of the tires, whether the tires were fully inflated or not and , lastlty, how effective the breaks were.
 
This is absolutely true. If the headlamp was on while it collided with the car, and if it was broken, the lamp itself will react in different way to the rapid exposure to oxygen. If this reaction is present, it would be clear the headlamp was on or not.
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There was a Las Vegas episode JUST like that.
 
Check to see if there are any titremarks or skidmarks. Look to see if there is any impact evidence , such as chips of paint on lightposts. ;)
 
One possible way to determine the speed of the motorcycle at the time of impact, from the given information, is to look for "speedometer needle slap".

When a moving vehicle suddenly comes to a rapid stop, it's possible for the speedometer needle to hit the inside of the speedometer. Depending on if it survives the impact, and what type of materials are used in construction, it's possible that the speed at the time of impact will be recorded by trace evidence transfer to the inside of the speedometer.
 
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