Video - MythBusters - Crash Force



Mythbusters crew decided to revisit an old myth that was drawing the ire of the show's fans for quite some time. And it's sure to be an interesting topic to automotive enthusiasts.

When two cars collide, each traveling 50 miles per hour, does the resulting force equal one car hitting an immovable object at 100 miles per hour?

It seems like such simple physics, no? But don't forget Newton's third law. To quote the great Wikipedia of knowledge, "Whenever a first body exerts a force F on a second body, the second body exerts a force −F on the first body. F and −F are equal in magnitude and opposite in direction." Or, more simply, for every action there is an equal and opposite reaction.

 

That was excellent!

I never questioned the idea of two cars at 50 equals one car at 100. But sure enough. It's not the same.

 

I actually never believed that myth. I never really protested against it just for the sake of not arguing or losing someone while I'm trying to tell them why its not true. I'm glad they did this to prove me right!

 

I'm kinda thinking they should've done it again with 2 older cars. Probably would've shown what technology has done to preserve the occupants. That wall didn't have the "give" that the head-on car had built into it. Also, they try to discount the theory that damage is increased exponentially with speed, saying that the 100 mph car was only damaged "about" 3 times that of a 50 mph car, the theory being that it should've been 4 times as great. Was this just based on their "educated guess" looking at it, or was there some data edited out I wonder?

 

Kinda off topic but, 2009 Chevrolet Malibu vs 1959 Chevrolet Bel Air . . . http://www.iihs.org/video.aspx/info/50thcrash

 

I'd have thought the '59 would have done better than that.

Crumple-Zones and air-bags DO work ............... however they also permit idiot drivers to be complacient while piloting 2 tons of steel down the public highways.
If Joe/Jane Schmuck didn't have all those 'built-in' protective devices, they'd think twice about trying to "Multi-Task" while behind the wheel.

 

Yeah, technology is certainly putting a damper on Darwin.

 

Looks like an awful lot of rust came out from under that '59...

 

Unlike politics, when opposite sides collide, nothing happens.

 

Yeah, I got that too. But their main measurement of damage was the length of the smashed cars and that has little to do woth the forces. The 2 foot or so extra reduction in length is not necessarily a linear measure of force. The G force recorders were way different in their readings too. Seems like a large error because both cars were identical and hit directly head on. So there are still some conclusions that are not clear about the whole deal. But the basic premise that the force of two 50 MPH head on cars is not equal to a 100 mph crash is valid. Interesting.

 

Yeah, but that doesn't seem like a valid excuse for the way the windshield post, etc folded right in on the passenger compartment. Are you saying the only reason it folded up like that is because it was rusty? Sounds like a conspiracty theory or something. New cars manage crashes WAY better than cars from 50 years ago. Big doesn't mean safe. Old doesn't mean better.

 

HEY! I am both fat AND old!

I believe that yes, some data sources were mixed (math and crash theory from investigation manual protocol). I belive they had to adjust for the composite factors, but the physics does match the much prevelent force theory. just commenting only from a law enforcement view.....amazing that Newton just expounded on one plus one equals ...Math is everywhere! (my son's quote).

 

But will they take off of the conveyor belt?

Sorry, couldn't resist..........

 

It could have contributed to the carnage.

 

It certainly could have, no doubt. But we have no way of concluding that it did or that what fell out was rust instead of dirt.

This was discussed the last time that video came to light here, and at that time as well, some made the point that it "obviously" was rust that caused it to fold up that way. I'm not convinced, and still hold that, "old" and "big" does not mean "safe".

Sometimes, it is what it is, and the '59 may just be very dangerous in a front end crash. Lots of work and lots of testing has gone on at GM and all the other manufacturers in the last 50 years. I thought that old and new crash was very interesting. Give me the new in such a crash!

In case you might pick the old, first check the steering column in the '59 as it comes right at the driver vs the airbag and collapsible column. BIG difference.