Does size matter?

[88Dakota]

 Originally Posted By: Win

Force = (mass)(acceleration). Obviously, size does matter. Wishful thinking that it doesn't won't help in an accident.

The purpose of crumple zones is to lengthen the time it takes to slow down to zero (i.e. the purpose is to lower acceleration) A smaller car may have less mass, but with a correctly designed crumple zone the acceleration can be made low enough to impart a smaller force on the rider than an older, larger car with more mass but nearly no crumple zone. Although now my mind is questioning...will each car not share the same crumple zone so-to-say? Maybe that would be putting it the wrong way...but it got me thinking.

 

[Spitty]

Yes the sum of the cars crumple zones can be considerd as one. However, at some point the car with the greater mass will push the lesser car backward, or out of the way. If the lesser mass car is pushed backward the G forces for the occupant will continue, if pushed aside, they will not. The point is, here we are ONLY talking Deceleration forces on the occupant, we are not considering injury due to loss of integrity of the cabin area, or injury due to a poorly designed steering wheel etc. A smaller/Lighter car (v a larger car) CAN be built to better maintain it's integrity in a high acceleration impact REGARDLESS of the other vehicles mass. Imagine a Baseball bat hitting a baseball, BIG impact (large force) Now imagine the same bat (at the same speed) hitting a Table Tennis ball!! If my grasp of physics is wrong here, I stand to be corrected.