I'd guess the wall, since cars are now designed to have frontal crush zones that would tend to increase the collision time.
skip
-----Original Message-----
From: Forum for Physics Educators [mailto:PHYS-L@list1.ucc.nau.edu]On
Behalf Of Herbert H Gottlieb
Sent: Thursday, February 17, 2005 07:18
To: PHYS-L@LISTS.NAU.EDU
Subject: collision question
Which would be more damaging, driving into a very massive concrete wall
or having a head-on collision with a similar car moving toward you with
the same speed?