'09 Malibu Vs. '59 Bel Air Crash Test

theodp writes "To celebrate their 50th anniversary, the Insurance Institute for Highway Safety crashed a 1959 Chevrolet Bel Air into a 2009 Chevrolet Malibu. Hate to spoil the ending of the video, but if you find yourself participating in a similar car-jousting contest, pick the Malibu over the Bel Air. (Not that you'll be complaining afterwards if you don't, or doing much of anything.) Guess there is something to those crumple zones after all."

Comments

Classic Cars

[Anonymous Coward]

Why would the pointlessly ruin a 1959 Belair? It's not like they make those anymore.

Re:Classic Cars

[blitzkrieg3]

I'm not sure why everyone keeps bringing this up. IIHS doesn't consider it pointless to demonstratably show how far we've come since they started improving vehicle safety way back when. Additionally, it's an easy way to showcase the importance of the organization to the general public, kind of like how NASA highlights it's spacewalks and additional modules to the ISS even though most of what they do is boring research.

Re:Classic Cars

[NixieBunny]

They shoulda used a 1958 model, considered to be the only non-classic late fifties Chevy.

Which is why I have one.

Re:Classic Cars

[Anonymous Coward]

http://wheels.blogs.nytimes.com/2009/09/18/more-details-about-1959-bel-air-crash-test/

"We didn't want to crash a museum piece," Mr. Zuby said. "We were not looking for one that had been restored for museum or show quality." But the vehicle had to have a solid structure, although a little surface rust would be acceptable.

They found what they wanted in Indiana. "The frame was sound and all the body panels were sound," he said. It had a 3.9-liter 6-cylinder engine and was in driving condition.

The car was bought for about $8,500 and had about 74,000 miles on the odometer, which was broken. It was trucked to the test center in Virginia.

Re:Classic Cars

[MBCook]

I just wish they showed the cars up close afterwards. While both are trashed, it's clear from the video that the A pillar just collapses on the Bel Air and the driver is probably crushed to death. Showing that (or whatever you can film) versus the still mostly intact cockpit of the Malibu would have driven the point home really well.

Re:Classic Cars

[los furtive]

They did: 09 Malibu and 59 Bel Air. RTFA and all that jazz.

Re:Classic Cars

[MachDelta]

You mean like this? :)

The pictures with the doors removed are simply amazing. Note how, not only is the Bel Air dummy folded up like a pretzel, but the entire body of the car has twisted such that the rear door no longer fits properly. The Malibu on the other hand is almost untouched from the firewall back. What an awesome demonstration of energy dissipation.

Re:Classic Cars

[Schmorgluck]

What part of "74,000 milse on the odometer, which was broken" did you overlook?

Re:Classic Cars

[AigariusDebian]

If the frame stays intact, but the body shears away in a shrapnel of sharp metal, then the frame is useless. The frame of the car in the video could have stayed 100% intact, but all the bodywork and engine and all crashed inside the passenger compartment ... then all of them are dead anyway. A tank is useless if in a 30 mph crash the engine flys off inside and kills all the crew.

Modern cars are safer by miles. Deal with it.

Re:Classic Cars

[RabidMoose]

And now, it's just a little bit rarer.

Re:Classic Cars

[interkin3tic]

Good news for the Bel Air owner though: the fuzzy dice looked like they survived mostly intact, although I think the string connecting them got ripped or cut.

Seriously, points to IIHS for including the dice. You can see them flying around the cockpit at 1:03 to 1:09. They look like they might present a hazard of as you are crashing, they might hit you in the eye, potentially causing you to blink and miss the carnage right before you die.

Re:Classic Cars

[Yvan256]

I bet it was the "which was broken" part!

If I'm the only one who bids, do I win? Like on eBay?

Re:Classic Cars

[Anonymous Coward]

As a restorer, I think it's a waste of a car.

As a mechanic, I think it's a pretty invaluable display of safety innovations in 30 years.

As a driver, I think they need to point out that the idea is to NOT CRASH.

Try slowing down, hanging up, and being sober. No amount of safety features can save a moron.

Re:Classic Cars

[Hurricane78]

I agree that classic cars have (emotional) value for most of us.

But your argument makes no sense. By that rule, child raping chainsaw murdering Arabian black Jewish gay Nazi women would be the best, and make us smile the most, because they are so rare. ;)

It rather is, because they are a piece of old art. Designs that you can't buy anymore. Technology that shows us what we once did badly or even better.

There's no reason to not include the crash test into that beauty.

Re:Classic Cars

[bev_tech_rob]

The 59 Bel-Aire wasn't that big a classic. Now crashing a '57 would have been a crying shame!

Re:Classic Cars

[Rei]

As a driver, I think they need to point out that the idea is to NOT CRASH.

No kidding! In the US we have this mindset that the only way to be safe on the road is to buy a giant armored tank and sit four feet off the ground. And so they buy a huge SUV which has god-awful maneuverability and is many times more likely to roll over. And who cares about the risk you put other drivers in (or pedestrians -- SUVs are several times more likely to back over a child, for example).

If everyone focused on light, agile, and well-built, the roads would be a lot safer place. I think it's quite telling that there's far more variance in crash survivability between vehicles in a given class than between classes -- even within the same price bracket. If the Smart Fortwo can pass crash testing with that tiny little crumple zone, it's pathetic that so many vehicles don't do any better than they do.

Re:Classic Cars

[10Ghz]

And no-one expected a Bel-Air to last 51 yeas either. If they did, why do we have all these complaints about wrecking a car that is so rare? Could it be that overwhelming majority of 51 year old Bel-Airs are in the heap, and only few are still around? I bet same thing applies to modern cars in 50 years. Overwhelming majority are gone, and few remain.

People look at old things and think "they build those things to last!", while they fail to understand that most of them have failed over time, and only handful remain. And since the thing in question (be it car, radio or whatever) is so rare, the few remaining are taken good care of, giving us the illusion that they are somehow more durable.

Re:Classic Cars

[David Gerard]

Reading TFA, they paid $8500 and made sure the engine and frame were in good order.

Re:Classic Cars

[drsquare]

I remember some studies where they removed all the lines and signs in some small towns in Europe and it resulted in many fewer accidents and an overall reduction in average driving speed. I really wish someone would try it in the US. We really need to remind our drivers that they are responsible for the safety of themselves and others.

If the US wanted to copy Europe on anything w.r.t. driving, it would be the standard of testing. Turning on the ignition, driving around the block in an automatic and parking again shouldn't get you a licence.

Then you need to abandon the concept of driving being a right, rather than a priviledge. But this might not be compatible with US suburban sprawl.

Re:Classic Cars

[silverspell]

"Gee, why is everyone complaining that they destroyed some old picture of a lady that wasn't realy smiling while comparing the materials available to Michaelangelo to today's?" :(

I think you've mixed up your Ninja Turtles.

Speaking as a non-car-freak

[Eevee]

All I can say is "You bastards! You murdered a car with tail fins! Have you no heart?

Re:Speaking as a non-car-freak

[Eudial]

The brown car had such an angry mouth, so it was probably not a very nice car. But the gray car looked friendlier.

Re:Speaking as a non-car-freak

[MachDelta]

How often do two vehicles on the highway hit each other dead-center head on? Front left fender vs front left fender is a more realistic approximation of a highway accident in my opinion. I'd take the Malibu.

Re:Speaking as a non-car-freak

[DG]

Actually, no, it wouldn't.

Notwithstanding the extra weight of the iron-block, iron-head inline 6, the Malibu's motor is still a substantial chunk of metal that can be considered essentially solid. You certainly aren't going to force the I6 motor THROUGH it.

What you will do is load up the engine mounts - which are much, much stronger on the Malibu, and designed to crumple in such a way that the passenger cabin is minimally infringed.

A more likely case in a 100% head-on collision is the Bel-Air's engine coming to rest in the Bel-Air's back seat, having been forced through the cabin by the Malibu.

DG

Re:Speaking as a non-car-freak

[davidphogan74]

I assumed it had to do with offset collisions being very frequent. Engine to engine crashes are fairly rare, but someone drifting a little over a center line isn't uncommon at all.

Re:Speaking as a non-car-freak

[Anonymous Coward]

Offset collisions are also more dangerous to cabin occupants than full, head on collisions. Car safety tests used head on collisions for a long time, but that was abandoned in the 80s or early 90s when it became apparent that they don't reflect real life accidents or the damage they cause to occupants.

The physical reasoning behind it is pretty simple: if you are offset, there is less material to soak up the energy of the crash. Typically enough that old school engine mounts or suspension parts would fail, and cause the drivetrain parts to intrude upon the cabin, like the Bel-Air's engine did in this test.

Re:Speaking as a non-car-freak

[dangitman]

I love it how you claim that a test by an organization with 5 decades of experience doing this is "bogus" just because of your uninformed "intuition" about old cars.

Re:Speaking as a non-car-freak

[AK Marc]

They did the test that way, not because they were rigging it, but because that's their standard offset crash test. It was done to simulate their crashes. The NHTSA did full-frontal crashes against a stationary barrier for years, and the IIHS called bullshit on that test. And the IIHS was right and the government was wrong. This test is a recreation of the offset crash test. That's much more likely to happen in the real world, and much harder on the cars.

And you are wrong about what would happen. My guess is that the engine would be stopped by the Malibu, and the Bel Air would end up collapsing around the engine, making the test that was fatal for the driver suddeny fatal for all occupants of the car. The Malibu, a leg injury for the driver, would turn into a foot and leg injury for the two front passengers. If you did the test they did with a full car, you get one dead person in the Bel Air and a minor injury in the Malibu. Make if full frontal and you get two minor injuries in the Malibu and five dead people in the Bel Air. And yes, though never employed as such, I have taken classes in traffic engineering and accident reconstruction.

the wunnerful 50's, not

[Ancient_Hacker]

Right around that year GM went to a wild X-frame design which allowed the door sills to be moved down several inches, making the cars easier to step out of. But the X was not very strong-- there were plenty of news photos showing Impalas broken in half by not very hard accidents.

Also if you look at a 50's car, the bumpers are massive but held up by a couple thin pieces of mild steel stock-- a strong toddler could bend them out of place.

Re:the wunnerful 50's, not

[Anonymous Coward]

But then again, back in the 50's we didn't need all these fancy crumple zones, seat belts and air bags. Men were real men. Hell, I'll bet you dollars to donuts any man from the 50's driving that Bel-Air would have jumped right out of that wreck to help the crying sissy-boy with a cut lip driving that Malibu.

Re:the wunnerful 50's, not

[SoCalChris]

My first car was a 57 Ford Custom 300 (Full size sedan). This was in 1995. The bumpers were massive and thick steel, and were bolted directly to the frame, nothing that a strong toddler could bend.

I was in an accident in it, a guy in a 1981 Toyota ran a red light and I t-boned him, going about 30mph. His frame was bent, axles were snapped, all side windows, the windshield, and rear window were broken. The frame damage snapped a few of his engine mounts, and also broke his radiator. His car was totaled. My car had the frame holding the headlight pushed back about half an inch, and scuffed the chrome bumper.

My observations were that I'd much rather be in an old tank like that in a minor accident. Anything major, and I'd rather be in a modern car with things like seatbelts, crumple zones and air bags.

Re:the wunnerful 50's, not

[afidel]

Nope, sorry but I would MUCH rather spend $1k than have my neck suffer 23G's of acceleration (what can occur in a 15mph crash without cushioning). That $1k represents a fraction of the monthly earnings for the average first world family, it's much cheaper to fix the car than fix the person.

Re:the wunnerful 50's, not

[poopdeville]

My observations were that I'd much rather be in an old tank like that in a minor accident. Anything major, and I'd rather be in a modern car with things like seatbelts, crumple zones and air bags.

"Minor" accidents can be much more severe if your body is taking the jolt instead of the crumple zones. Injuries like whiplash are extremely common in "minor" accidents. You might be able to get your Ford's frame straightened, but you can't get your neck fixed anywhere as cheaply or easily.

30 mph is not a minor accident, by the way. That's like falling out of a second story window (taking into account conservation of momentum leading to smaller forces on your body)

Re:the wunnerful 50's, not

[anagama]

Modern car crash: $1000 for bumper and $0.10 for bandaid, total: $1000.10

Old car crash: $50 to mend scratch on bumper, $7500 for head injury, untold lost earning power because now you're an idiot, total: $7550+

Re:the wunnerful 50's, not

[4D6963]

My observations were that I'd much rather be in an old tank like that in a minor accident. Anything major, and I'd rather be in a modern car with things like seatbelts, crumple zones and air bags.

Yep, that's why before getting involved in any traffic accident, I always carefully choose the car I own which would be best suited. Now if you'll excuse me, I might accidentally run over my neighbour in his backyard while I'm on my way to the store. I think I'll pick the Hummer, it's the better one to get through wooden fences.

Re:the wunnerful 50's, not

[Comatose51]

Ah yes the good old 50's, when men were men and women were property.

Re:the wunnerful 50's, not

[Stevecrox]

Crumple zones were added into cars because of the high number of injuries sustained in car accidents in rigid steel frames cars. The whole point of a crumple zone is for it to crumple reducing the collision energy which reduces the shock to the people inside which reduces the number of broken bones. In essence you want the new car to be wrecked, if its wrecked that means much of the collision energy was used in crumpling the frame of the car and not in jolting the passengers.

It's just one of those things car designers learnt from trial and error, like where to put a petrol tank so it doesn't explode and why not to use metal steering wheels.

I tried to find the European NCAP rating for the Malibu but wasn't able to so i have no idea on how safe the car is. But a while back on Top Gear they felt so safe about a 5 star NCAP car a presenter crashed it into a wall at 30/40MPH he came out without a scratch. Admittedly they'd wrecked the car, but the presenter didn't even have whiplash, you just wouldn't do that in a 50's car because chances are you'd end up with broken legs or internal injuries (generally from the steering wheel). Sure you were fine, but those changes happened because most people wern't ok.

Re:the wunnerful 50's, not

[Lonewolf666]

"Minor" accidents are something like 5 mph. Around 1980, regulations (http://en.wikipedia.org/wiki/Bumper_(automobile)#Strengthening_standards actually required the bumper to handle that. I once had a 1989 Opel Vectra whose bumpers still seemed to match that requirement, and it has saved me a nice chunk of money.

But I agree that you should not expect the bumper to handle a 30 mph crash.

Re:the wunnerful 50's, not

[darkmeridian]

My brother works in an emergency room. He notes how fragile the human body is compared to the interior of a car. A patient of his was admitted from a minor car accident where he was rear-ended at least than 20 mph. The patient, who did not have his seat belt on, slapped his head against the steering wheel. That opened up a gash that required dozens of stitches.

You can very easily be in a heavily-built car but suffer severe injuries in a relatively minor accident if you are not buckled up. A newer car would crumble to absorb the shock. The tank would hold its shape, then slam into you as you're held in place by inertia.

'52 Citroen DS

[drerwk]

CitroÃn had unibody, disc brakes, and the equivelent of crush zones. The were required however to put a 5mph bumper on the car instead of the 4kph as in europe due to US insurance demand. Would like to know how the test would have looked against a Cit.

I see the problem.

[SilverHatHacker]

It should have been a reverse Bel Air.

Now this is a story all about how my life got flip turned upside-down. I'd like to take a minute, just sit right there, I'll tell you how I totally destroyed a classic car in the name of science.

YouTube Commenters strike again

[the Dragonweaver]

The comments on the video are rather telling. A number of people claim the video must have been faked, because "The Chevy would have barely gotten scratched."

Notably, a number of the panelists on the hearing about the sinking of the Titanic expressed serious doubts that mere ice could have torn iron. In other words, time marches on, but ignorance of physics remains a constant. (Also see, "This is the first time in the history of mankind that fire has melted steel.")

Re:YouTube Commenters strike again

[Anarchduke]

There are many aspects of old tech that are still superior to current tech. The primary reason it isn't done is cost of manufacturing. All this "self-evident, 50+ years of engineering" nonsense is quite presumptuous. Hitler used similar arguments making the case for white supremacy. Business buys results, not pure research.ï This is a propaganda ad pure and simple. Go check who paid for this to be made and who profits from it.

The YouTube stupidity wasn't limited to claiming it was faked. Here we have an actual YouTube commenter trying to draw a comparison between Hitler's Eugenics program and the engineering principles behind car safety. It's like crazy in a can.

Re:YouTube Commenters strike again

[the_raptor]

All cars now also come with seat belts and most people wear them.

Re:YouTube Commenters strike again

[Eudial]

The YouTube stupidity wasn't limited to claiming it was faked. Here we have an actual YouTube commenter trying to draw a comparison between Hitler's Eugenics program and the engineering principles behind car safety. It's like crazy in a can.

You must be new to the Youtube comment section. Welcome.

TopGear

[CountBrass]

A recent TopGear did something similar: they crashed an NCAP (European crash standards body) 5 star+ rated (the highest rating) car (Renault Espace) into an earlier model of the same car (a 1998 Espace I think it was) at 35 mph.

The crash investigator they had evaluate the results said the driver of the older car would have had multiple broken bones, including both femurs, and even if he'd survived the crash he would have bled to death by the time they could extract him, which would take 30-40 minutes as the car was so badly deformed.

In contrast, the modern Espace's computers decided the crash wasn't bad enough to deploy the air bags! Only the seat belt pre-tensioners fired. The investigator thought everyone in that car would have walked away from the accident uninjured.

Their conclusion was that modern crumple zones and stiffer chassis work but because they are stiffer older cars suffer much more when colliding with a modern car.

What always surprises me is how much damage is done to any car, old or new, at these low speeds! Really says to me that any speed limit over 40 mph on any single-carriage way road is just insane.

And some follow up comments

[TubeSteak]

A few people were calling shenanigans, claiming there was no drive train or that the IIHS used a vehicle with a rusted out frame.
So a writer for the NY Times caught up with "David Zuby, the senior vice president at the institute's crash-test center in Virginia"
http://wheels.blogs.nytimes.com/2009/09/18/more-details-about-1959-bel-air-crash-test/

Re:And some follow up comments

[DG]

OK, so if you have a collision, you have kinetic energy that WILL be dissipated. It's is going to go somewhere; it cannot just be swept under the rug.

If you make the car 100% rigid and ensure that the driver is tightly secured - as some NASCAR feeder series cars were in the late 80s and early 90s - then that energy is fed into the occupants. Subject them to 50Gs and you start ripping hearts loose in chest cavities and inducing massive concussions as the front of the skull decelerates the brain. This is suboptimal for survival.

So the car's structure has to be designed to dissipate that energy to a survivable level. Plus street cars don't have the luxury of securing the occupants as tightly as race cars (and putting them in helmets and HANS devices) so secondary impacts within the cabin are a real concern.

A properly-engineered crumple zone not only dissipates the energy of the crash, it crushes the structure in such a way that nothing intrudes into the passenger compartment, that doors remain closed, but yet the door frames remain mostly intact so the doors can be opened more-or-less easily post impact. Granny in the back seat isn't going to be crushed by a flying engine block that winds up in her lap, and little Jimmy isn't going to bleed to death while the EMS crew watches because it takes a hydraulic ram to wrench the door open to get at him.

The crash engineering really is amazing. It is incredible just how well the structures are tuned to maximize occupant survivability.

And pedestrian survivability as well. Almost a third of "Unsafe at Any Speed" (credit the devil, Nader wrote a groundbreaking book) was dedicated to discussing vehicle-vs-pedestrian impacts, and how decorative designs like the "missiles" on the hoods and bumpers of the cars at the time were inflicting horrible wounds on people struck by them. While being hit by a car is always going to be a serious, traumatic event, you are much better off being struck by a modern car than by a "classic".

In every measurable way, modern cars are so much better than cars of just 20 years ago that it is utterly amazing - and cars 50 years ago are, in comparison, steam locomotives.

DG

that would be Fifth Gear

[YesIAmAScript]

Top Gear tries to stay away from useful facts and info as much as possible.

And the idea of Top Gear having TWO cars that cost below $40,000 on the screen at the same is pretty far fetched.

Re:that would be Fifth Gear

[Joce640k]

Is *anybody* here under the illusion that watching Top Gear will help them choose their next car? Sheesh.

Re:that would be Fifth Gear

[Hurricane78]

Exactly. Top Gear is about fun and entertainment. And they're doing a very good job in that department!

Fifth Gear is the boring but useful relative.

It's like with women: They need the latter, but they love the first one. And while the second one helps as much as he cans, just to be loved, the first one is loved specifically because he is exciting rather than useful. Poor Fifth Gear. Will he ever realize what the problem is? ;)

I drive a 58 Chevy...

[NixieBunny]

...so this test was especially interesting for me. Remind me to keep to divided highways in the future.

One reason that the door crumpled so readily is the crazy wraparound windshield. The windshield pillar contains a free-hanging right angle, which is not the way that a structural engineer would have done it. It also bangs the knees.

The big problem with older cars is that the body shape was sculpted from clay in a studio separate from the rest of the car designers, rather than being designed as part of an automobile. The end result being that the body shape had no basis in sound mechanical design.

Re:Patiently waits

[tsm_sf]

and that cars should have a spike on the steering wheel reminded me of an old Letterman top 10... thank you, Internet!

Top 10 Ways American Cars Would be Different if Ralph Nader Had Never Been Born


10. Dashboard hibachis
9. Seat belts made of piano wire
8. Windshield replaced with ant farm for kids
7. Strobe headlights make oncoming traffic look like old time movie
6. 50-foot antennas allow you to broadcast while driving
5. Optional front-seat hammocks
4. Wiper fluid reservoir routinely filled with thousand island dressing
3. New York City taxis would be exactly the same
2. The paper Buick
1. Speedometer replaced with electronic voice chanting "Punch it! Punch it!"

And this repels morons?

[Kupfernigk]

So "caring about driving and their car" mysteriously repels the morons who jump lights, drive too fast on wet roads, overtake on blind bends, or drive the wrong way down divided roads?

My friend, many motorcyclists care deeply about their bikes, but that does not prevent surgeons from referring to them as "organ donors".

Re:And this repels morons?

[Comatose51]

They've also contributed greatly to the field of psychology and neuroscience by demonstrating what parts of the brain is responsible for what cognitive function.

Re:Pointless Sensationalism

[osu-neko]

And why do they collide at an angle, because that definitely favors one style of construction over another - frame, engine placement, driver's side vs. passenger side, body materials, bumpers, etc.

Because in the real world, cars collide at an angle just short of 100% of the time. Getting an actual, straight, head-on collision is a very difficult task that requires a great deal of setup and effort on the part of the people doing the testing. In the real world, drivers don't arrange their crashes with such mathematical precision. "at an angle" is pretty much a given...

Re:I call shenannigans!

[poopdeville]

I have a hard time believing that you can predict that. Why do you think the Bel-Air's block would "cut through the Malibu" instead of cutting through the Bel-Air's cabin, like it essentially did in this test?

Re:How about some REAL bumpers?

[Rakishi]

Mainly because they don't look as nice.

That said, a car accident has a massive amount of energy involved even at low speeds. That energy has to go somewhere. In a new car the energy goes into destroying the vehicle or parts of it. In an old car the energy goes into throwing the driver around. Essentially, at some people people decided that losing a car is preferably to losing their life or suffering life long disability.

Re:Where's the engine?

[interkin3tic]

The straight 6 engines in those cars offered no protection in an offset crash, and just smashed back through the dash killing the occupants, who were dead anyway.

Fucking classic-car-driving zombies...

Car repairs are cheaper than orthopaedic surgery

[spineboy]

I'm an orthopaedic surgeon, and wind up taking care of a lot of people from car accidents. Even a 10 MPH crash is enough to cause whiplash.
Car repairs are much, much cheaper than hospital bills, and there are some things that we aren't still good at fixing like cartilage damage, and whiplash - who likes chronic pain?

Well, if they were dead anyway...

[Chas]

Then they wouldn't mind being killed a little more would they?

Have a look at race cars

[Sycraft-fu]

When those things wreck, they disintegrate. The whole car seems to come apart, and you are amazed the driver could survive. However, it is BECAUSE they come apart like that that the driver survives. They have a rigid cage enclosing the driver, and a compliant body. That way the body takes the massive energies involved in the rapid acceleration to a stop, rather than them being transferred to the person.

That whole pesky F=MA thing applies to cars just as well as anything else. When a massive object like a car rapidly accelerates to a stop, there is a shit ton of energy. How that energy is dealt with and dissipated can be the different between a person having a bruise, and dying from their internal organs being destroyed.

Re:Have a look at race cars

[snowgirl]

I really like formula-derivative cars for demonstrating the point of "destroy the car, not the driver" idea. You see an F1/Champcar/Indie car collide with anything and its just parts flying everywhere. I point out to people "each chunk of metal flying away from the crash is a bit of mass, and velocity not flying towards the driver".

I think that's the coolest thing about car-design safety in racing. It's made drivers much more likely to survive, and vids to watch just HELLA way more cool...

I mean, when a girl gets excited watching cars blow up into a million pieces (because I obviously didn't know the person in the car) you know it has to be impressive!

Re:Combined speed?

[hackerjoe]

Your physics makes no sense. Why is this modded informative? The ground is not a magical reference point!

If two cars travelling in opposite directions at 40 MPH slam into each other, that's exactly equivalent, in terms of energy dissipation and momentum transfer, to one car travelling at 80MPH slamming into a stationary vehicle. Each vehicle, in its own reference frame, sees another vehicle travelling at 80MPH.

Think about it: if two identical cars crash, and one is stationary, then for a moment (before they come to a stop due to friction against the pavement) they'll be moving together at half the speed of the moving car before the crash. One car goes from 80MPH to 40MPH (40MPH difference); the other goes from 0MPH to 40MPH (40MPH difference).

This is exactly equivalent to going from 40MPH to 0MPH (40MPH difference).

When you're working out simple kinematics like this you should be starting with momentum, which is linear with velocity. You can work out how much energy is released afterwards; you'll see that it works out:

(1/2) * (1500kg) * (36m/s) ^ 2 = 972 kJ - Amount of kinetic energy in the moving car at 80MPH
(1/2) * (1500kg) * (18m/s) ^ 2 * 2 = 486 kJ - Amount of kinetic energy left after the crash: 2 cars at 40MPH
972 kJ - 486 kJ = 486 kJ - Amount of kinetic energy dissipated in the crash

(1/2) * (1500kg) * (18m/s) ^ 2 * 2 = 486 kJ - Amount of kinetic energy in 2 cars at 40MPH
(1/2) * (1500kg) * (0m/s) ^ 2 * 2 = 0 kJ - Amount of kinetic energy left after the crash: in 2 cars at 0MPH
486 kJ - 0 kJ = 486 kJ - Amount of kinetic energy dissipated in the crash

(Yes, kinetic energy is 1/2 mv^2, not mv^2!)