MythBusters - Crash Force - awesome test

[gary0006]

Video - MythBusters - Crash Force (http://www.dpccars.com/car-videos-10/05-08-10page-MythBusters-Crash-Force.htm)

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.

[Matra et Alpine]

it clearly won't because in a head on BOTH cars deform approxinately equally given equal cars.
A wall wont' deform so the car receives much higher deformation.

Mythbusters wastes too much time showing when the simple laws of physics woudl ahve covered it :)

[LeonOfTheDead]

Despite the mere quoting from autoblog by the OP, Matra is right.
Deformation is something to consider in this aspect, would have been a better idea to crash one car at 100 mph against another identical standing car.

Still, what they should have talked about a little, is energy, kinetic energy mainly.

With one car, weighting about 1.500 kg, and going to 50 mph (80 km/h), its kinetic energy is 370.370,4 Joules.
Two cars crashing at that speed one against each other, release twice that energy, dissipated in many ways. Sounds, deformation, heat etc etc, hypothetically divided equally between the two cars and nothing else, so each car gets 370370,4 Joules.
Crashing only one car against the wall release the same 370370.4 Joules, almost completely absorbed by the car. No wonder if the results are the same then.

One car at 100 mph (161 km/h) crashing against a solid wall, release an energy of 19.344.270 Joules, which is about 52 times more. Almost all that energy is absorbed by the car, with a minor part of energy being also absorbed by the wall.

Another aspect to consider is that the deformation of the car changes at each section of itself, so while the bumper is deformed easily, the cockpit is the strongest part and will require a lot of energy to be deformed. What I'm trying to say is that the same deformation caused by a certain energy could be matched by a slightly higher energy, if the next part to be deformed need much more energy to be, well, deformed.
It sounds silly, but take it this way. The bumper needs say 1.000 Joules to be deformed. The next part behind it its say the engine, which needs 10.000 Joules to be deformed.
Very hypothetically, 5.000 Joules would cause the same damages of 1.000 Joules.

On the other hand their small scale simulation have a deformable part which isn't as complex as a car absorbing energy and being deformed.

So a spectacular experiment, which may generates even more myths.

[coolieman1220]

forget the physics,

this shows korean cars are UNSAFE!

wow at the 100mph...

[NSXType-R]

That's some pretty cool stuff.

I'm taking physics next semester.

Fun.

[Matra et Alpine]

Haven't seen it cooliman, but have seen MANY similar tv "shows" who put the show ahead of the teaching :)

Cars dont' survive 100mph crashes in to walls very well at all.
Leon's analysis on the ENERGY is the key point. All that energey goes SOMEWHERE.

AND ... if you build a VEHICLE to survive the crash "better" than by definition most of the energy now isn't absorbed and disipated over time and the CONTENTS of the vehicle sufffer. There is NO point making a vehicle to not crumple to near nothingness in 100mp frontal. The passegers are dead in the first 50msec anyway :(

[coolieman1220]

Haven't seen it cooliman, but have seen MANY similar tv "shows" who put the show ahead of the teaching :)

Cars dont' survive 100mph crashes in to walls very well at all.
Leon's analysis on the ENERGY is the key point. All that energey goes SOMEWHERE.

AND ... if you build a VEHICLE to survive the crash "better" than by definition most of the energy now isn't absorbed and disipated over time and the CONTENTS of the vehicle sufffer. There is NO point making a vehicle to not crumple to near nothingness in 100mp frontal. The passegers are dead in the first 50msec anyway :(

yeah its not often you hit a straight wall at 100mph that doesn't move. its pretty dangerous. the G load is nuts.

[RacingManiac]

Energy makes for poor prop on TV.....

Mythbusters is crossing the point from being entertaining to science, and that is starting to put their methods to question more and more....

[Matra et Alpine]

Mythbusters is to science knowledge TV
as Top Gear is to balanced auto reporting.

Both out for the hell of it and to have fun :)

[Ferrer]

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