Originally posted by: DrPizza
	
	
		
		
			Originally posted by: liquid51
 Like a car hitting a brick wall at 60, or two cars hitting head on at 30 each. same forces applied.
Oh lord, I'm rambling. My apologies. And if my thoughts are unclear or I can be corrected by someone else, please interject.
		
		
	 
interjecting:
two cars hitting head on at 30 each isn't the same as 1 into a brick wall at 60.
For help understanding this:
Get a great big sheet of kevlar or something that wouldn't allow the driver to see what it just impacted. 
a) put the kevlar against a solid, unbreakable (by the car) brick wall. 
b) hand the kevlar at a position such that an identical car will strike the other side at the same time.  
In both cases, the car will go from 60mph to 0mph.  (unless it bounces off) 
The kevlar, for the most part, will remain relatively stationary in the center between the car and car or wall. 
The only difference is that in the brick wall case, the wall (not breaking), will absorb some of the energy in the form of heat.  (I was corrected on this point about a year ago in this forum)