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Old 08-01-2010, 05:45 PM
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Peter Ward
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Peter Ward is offline
 
Join Date: Dec 2007
Location: The Shire
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Quote:
Originally Posted by glenc View Post
A 40 tonne truck traveling at 100 kph produces the same force in a crash as a 2 tonne car traveling at 1,000 kph.
I am assuming the stopping distance (amount of crumpling) for the truck is 0.1m and the stopping distance (amount of crumpling) for the car is 0.5m.
The vehicles are not crashing into each other.
Maaate...in that case you have used the wrong equation.

F=ma
a= Dv/Dt (change in velocity)

Soooo......we need to know the *time* it takes to go from go to whoa.

This is not a simple calculation, as the full momentum of an articulated truck may take some seconds to be absorbed, and cars vary enormously in how much "crumple" they have before they stop.

The *energies* are equivalent at 100km/hr and 447km/hr respectively.
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