The Physics of Car Crashes
Вставка
- Опубліковано 29 сер 2024
- How is the chemical energy of gasoline transformed into kinetic energy of a moving car? And where does that kinetic energy go when the car crashes into something and stops moving?
Thanks to Ford (www.takeagoodlo...) for sponsoring this video.
Link to Patreon supporters here: www.minutephysi...
Music by Nathaniel Schroeder, / drschroeder
MinutePhysics is on Google+ - bit.ly/qzEwc6
And facebook - / minutephysics
And twitter - @minutephysics
Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich
“Speed has never killed anyone. Suddenly becoming stationary, that's what gets you.”
― Jeremy Clarkson
I agree
+I'm not your buddy, friend Suddenly becoming anything, really
(eg. pedestrians being hit by a truck suddenly picking up a lot of speed)
Newtonian mechanics in a nutshell.
lol
+I'm not your buddy, friend unless you're going so fast that you start shredding apart
Thanks for using metric units!
+Linken Still using silly things like teaspoons and "a third of a cup" though :(
+Linken
Go back to Un'Goro!
+MJDHX Haha u get it
+melig1991 Easier than 233ml and 23 grams don't you think?
Metric units are used by the entire world but 'murricans and teaspoons and cups are also used by all the chefs and cooks...then again this is a pseudo-science channel.
Uhmn, wouldn't kill them to use both? one narrated and both written. Everyone happy!
+Raik This isn't pseudo-science, i think you mean popular science.
This is really cool. A good way to counter the people who say that "cars were better back in the day"
+TheKimpula People generally mean they looked better, which is true.
+TheKimpula They were absolutely worse in about every conceivable way.
+superdogmeatmeat Except in retro feeling ;)
+superdogmeatmeat They looked better and they sounded better.
+TheKimpula If you have a small bump with a car nowadays, you'll most certainly have to pay a new bumper, while with older cars you'd at most have a scratch in the paint. When they say "cars were better back in the day" that's what they're refering to, so i dont really see what this video counters in anything
Doing a joke about petrol would be fuelish
aha
+Kishore Shenoy Go electric! Everyone is fuming over the high cost of gas.
+Kishore Shenoy No. That would just be bland, expectable, repetitive, unimaginative and dull. So pretty much like any other English household pun.
+Kishore Shenoy Lol! Nice one! :-p
+Kishore Shenoy There is no way you could fit comma into that sentence, even if it was part of the pun, which itself is already horrible enough.
Crunchiness is something that good cars and good candy bars have in common.
😂😂
this is why the tesla model S has such a good safety rating. with no engine in the way, the entire front section is a huge crumple zone
+BattMarn That should be the case for the majority of sport cars then. Given that they usually have the engine at the back...
+StephanDRX "most" sportscars?
+StephanDRX yeah, no. because there's no engine in the back either in the tesla, so there's less weight moving around and therefor less energy to dissipate. most of the weight of that car goes into the batteries, and those are low down under the floor. but i guess mid and rear engined cars are a bit safer in a frontal collision.
+GraveUypo Less weight moving around? The batteries are HEAVY and the car weighs just above 2 tonnes. That's much more than an average modern car.
+Gurgumul Thanks, you take the words out of my fingers.
And what about side crashes?
+KinRedysko check mate atheists
+KinRedysko A side-crash only has about half of the impact of a head-on collision so they're overall less dangerous.
Jason Slade
Are you freaking kidding me dude? getting hit in the drivers side door is THE worst place to get hit in a car accident. That's why we have tools made by a company called hurst, not only do they make cool shifters and race car parts, they also make the rescue tools that firefighters and emt's use to extract you from those same vehicles. Do a youtube search for vehicle crash side extraction if you want to see why you don't want to get hit on the side. There is so much metal in front of you that can crumple and collapse in a front collision, in a side crash, you have some 18 guage sheet metal that will usually crumple up like a tin can, your only saving grace is usually the A and B pillars, but the impacting vehicle usually severely bends your door inwards and goes between them which collapses the survival space you have in the passenger compartment.
+KinRedysko That is why car doors are quite thick, and why there are side airbags. But side crashes are still definitely more dangerous.
+Peter “Crackpot Pete” Carlson Way to take his comment completely out of context. He never said it was better, he said there is less force in the impact. This is because when you crash head on, you're velocities are additive, as if you're going twice as fast and hit a wall. however, if you get hit from the side, your velocity doesn't matter, it's just the car who hit you.
Hooray for sperm teaspoons!
+MrEnte3000 To the top!!
+geico1989 I spot a 9gagger
+Herny Chen someone give this guy a cookie
+Herny Chen yup
*****
Subscribe to yourself.
Another technique is that the engine is designed to be deflected down under the safety cell. This is good for 2 reasons. The first is that the engine is pretty solid and can't be compressed. The second is that the engine is heavy but by deflecting it down under the car it doesn't have to decelerate gently and the crumple zones don't need to worry about absorbing all that energy. Let the engine hit the tree and come to a dead stop while the car is "gently" decelerated by the crumpling above it.
"Cars are carefully designed to crumple when they crash."
I guess the Cybertruck designers missed this part.
there’s like a good 1-2 feet of crumple, and there being no engine makes that do a lot more than you’d think
But it is not designed to crumble because of the whole you will win in a confrontation with another vehicle thing, so the might be amzing potential, but it is not really Happening
@@jasperfromming6633 Crumple zones exist for a reason. They absorb energy and reduce the acceleration experienced by the passengers. An extremely rigid car will cause serious internal injuries in a collision with a rigid and immovable object. The high mass might be benefitial for its passengers in a collision with a lighter car, but dramatically increase the risk for passengers in the other car. The concept is flawed, if every manufacturer built cars the same way traffic casualties would skyrocket.
@@nicorosbergf1fan783 thats why i hate the cybertruck, sorry that was not clear from my previous comment
@@jasperfromming6633 Ah sorry I misunderstood
I liked the part about how inneficient fuel engines are... that's crazy.
+Martin Brochu Engines need radiators for a reason.
+Martin Brochu We could do a little bit better -- up to 50% of the fuel energy could be converted to kinetic energy -- but that would require removing a lot of safety features and it would probably destroy the engine pretty quickly. So it may be inefficient, but it's a lot less wasteful than you might think.
+Martin Brochu Now compare them to electric motors, which all have an efficientcy above 90%, some of which going up to _friggin 99.7%_!!!!
Problem is, you need batteries, which have - at most - an efficency of about 60%.
If we would be able to improve batteries, someday it will be more efficient to burn the fossil fuel in a powerplant (where much more efficiency can be achived than in a car...) and then power electric cars with it... only those damn batteries....
+Merthalophor To my knowledge, batteries of today are far more efficient, close to 100% under 70-80% charge.
+Martin Brochu And you know what? They're extremely efficient in terms of directly converting fuel into work, especially if you add a turbocharger and harvest energy from the exhaust.
Your last point is excellent. A dent or crease in the wrong place can dramatically reduce the yield strength of that component, thus reducing it's ability to absorb that crash energy.
If I understand you correctly, although dings and dents might be aesthetically unpleasant, it's important to get them repaired anyway, because some of the part's energy absorbing (crushing) ability has been removed from the part, thus compromising its ability to absorb energy through crushing in subsequent collisions.
I think this is one of the most informative videos I've watched here,I had no idea that the front of the car does that. New appreciation to it.
Now you know how a Mercedes bends
Mercedes Benz?
I love watching your videos and while working on my driving school, this video showed up and made my class so much better! Keep up the amazing content ❤❤❤
A new car built by my company leaves somewhere traveling at 60 mph. The rear differential locks up. The car crashes and burns with everyone trapped inside. Now, should we initiate a recall? Take the number of vehicles in the field, A, multiply by the probable rate of failure, B, multiply by the average out-of-court settlement, C. A times B times C equals X. If X is less than the cost of a recall, we don't do one.
+Gytax0
And which company did you say you worked for?
"The one that sponsored this video."
PS: It wasn't the rear diff locking up, during rear-end collisions the bolts sticking out of it would puncture the fuel tank. Hence the fires. (This was a real thing that happened.)
+Excluded Layman good old Pinto. It's a pretty famous case of class action lawsuits.
Fantastic stuff Henry. I'll show this to my classes after Christmas when we're preparing for exams!
You should have added the purpose of airbags, which are also designed to decelerate your body vs the car.
What is often mistakenly assumed is that airbags are soft cushions that hit your face, but if that were the case, they would shred apart from the explosion and your face would be hit by a huge amount of shrapnel from the airbag's micro-explosion.
Instead, airbags are actually made of a material that is similar to a basketball so that they could withstand the pressure of the sudden inflation, and when they hit you in the face, it really feels like a basketball thrown right into your nose.
When I asked a friend of mine, who is a firefighter, abour car crashes, he told me about an observation he did.
More accidents with low speed cars (like 30-40 km/h) were fatal for the driver in relation to accidents with arround double the speed.
Our explanation was that the engineblock gets crushed at arround 70 km/h but is pushed into the driving compartment when on lower speed consequently killing the driver.
Needless to say that there is an upper Border of speed to make this work, since there is only so kuch energy the engineblock can take until it is completly crushed.
Ah very informative. It is astonishing to know what level of engineering and Physics goes into making cars and other machines of our daily lives. Thanks for such a nice video.
This helped dispel the myth that older cars (being an older guy I remember those old "solid" cars) are safer than the newer, lighter vehicles. Sharing this!
Oh, thanks for uploading this 4 days before my driving test. :D
a full day is now 22 hours?
Lol
Toasters sleep for 2 hours per day
You can't have a toaster in "power cycle" continuously. (Unless maybe you deliberately short over the thermal sensing part of the circuit to burn an open in the NiChrome wire heating element rather quickly)
Do you know what I like more than crashing cars....?
KNOWLEDGE
+AkosoPlays Aw don't crush that Lamborghini
+AkosoPlays nawlage
+Simon WoodburyForget When it the best thing you can do... if your an idiot
...and this video is epitome of why we love physics.
Excellent work as usual, Henry!
0:29 Funny, I've seen the exact same teaspoons in my biology book.
Yeah I thought they looked like a certain something else, aswell
@anastashia My biology book, can you read?
I thought it takes 5 teaspoons of sperms to power a car...*facepalm*
Me too
From 1:38 - What if the beam/the front part is replaced with Spring/coil? which can be absorbed energy and divert it to ground.
Crash? I think you mean rapid unplanned dis-assembly!
+Bram42 Lithobreaking is a perfectly cromulent method of slowing spacecraft!
LIGHT SPEED!
off topic: can you do an episode on internal combustion engines? I've always wanted to know how they worked
Awesome! Thanks Henry and Ford :)
....Henry Ford. :O Omg!
I wish he would've talked more about how speed and such affect accidents, and perhaps also make a "Drive Safely" PSA. I think more people would listen to Henry about the dangers of driving than the Secretary of State.
great video!
Crashed my car a couple months ago going about 70 km/hr, the car was totaled and I barely got a scratch on my elbow that didn't even leave a mark. Cars are absolutely safer nowdays
As if I can afFORD a car.
Get it?
Ok I'll go away....
Hah
Hey
Thanks!! I love your videos ! You can explain so good! I like your concept of drowning by hand the graphics and your funny animations!
I love your videos. Greetings from Germany
Awsome video, but you should have also discussed the designed give of a seat belt. And the awesome speeds of the airbags. Ive been in a car crash before, t wasn't fun.
Great video, but I also really wanted to learn about head on collisions, like the transfer of energy involved and the different forces during the crash
I did not know that, I just figured air bags were the only thing keeping us alive in crashes but this is amazing explanation :)
0:28 That doesnt look like gas to me...
I'm a car modder, but not like scraping the pavement and loud exhaust on a small Japanese car haha. My current project is making a 83 vw to be the most crash resistant. I'm trying to find a blend between avoiding permanent damage to the vehicle and absorbing impact. The read bumper mounts which are normally designed to crush have a large coil spring to help reduce permanent damage while the fronts have a fault zone at a cheap, easy to replace and easy to crush bracket that cost $4 to make/replace per side. My goal is to be able to get in an accident rear ending a car at 20mph then to be rear ended at 20mph and to only have the two front bracket to replace. Of course in testing it out on a large tree and not on the freeway haha
a lot of people actually want to drive a batmobile
It's just death
Many people believe that if you crash head to head with another car, both cars having the same speed, is like cashing straight into a wall with double the speed. My driving instructor told me that during my driving lessons and we pretty much argue because I was saying that it doesn't matter if you crash into another car (of the same mass) or into a brick wall. But how do we prove this? I justify this to myself like this: 1) in the first situation, the energy equals the kinetic energy of the 1st car plus the kinetic energy of the second (which is the same, because of the same speed the cars have). Now after the crash the energy has to stay the same as before the crash. So the two cars after the crash actually exchange energy, that is why both cars get crumbled. 2) In the second situation, the energy equals only to the kinetic energy of the car (as the wall doesn't move => no kinetic energy). So, just like the first situation, the energy has to be the same before and after the crash. when the car crashes into the wall and provided the wall doesn't get destroyed, the energy gets mirrored back to the car. If the car crashes into the wall with double the speed the energy that is returned to it would be 4 times more, so the damage to the car would be way even bigger.
to all those people saying first here, you're wrong! this was on vessel first
+jojidubi4 Is that still a thing? Haven't heard about it for months.
+jojidubi4 Who's on first?
+SteevyTable
Who
WHAT ARE YA ASKIN ME FOR?!?
I just answered your question.
If the car's fast enough, can the crumple zone become a death zone? Also, I'll be very pleased if you make one video on Airbags.
im going to buy a ford now. goodjob
This is pretty much my favorite channel
Cybertrucks bad? 😮
My exact first thought! 😂
Yes yes yes yes yes absoulutly i was going to comment that! More people need to know that
Ive tried to explain this to so many old people who lament that cars "plastic" now instead of metal.
2 dislikes and it hasn't even been long enough since the upload for one viewing. xD. Seems like we have some trolls.
I see 4 dislikes
+crasowl It's called dislike bots, UA-cam 's full of them, their programmed to instantly dislike a video has soon has it is uploaded. Why would anyone install such a thing on their computer however is beyond me...
+Hugo Sousa
Really? Is that true? I always that there were a few people that disliked for the heck of it.
Maddix I'm sure there are also a few people who do that but the bots thing is really has well
Since you were talking about organ difsormations, and wounds, maybe you could try to make a serie of videos about imaging techniques, as these imply a lots of physics, and most people barely understand the whereabouts of MRI (uh, you go in a big magnet and boom, pictures), PET-scan (with a dog? a cat?), and other techniques. It could give people more insight about the pro's and con's of each technique, and maybe allow them to have an idea of what they undergo when they go to the hospital.
(maybe even for medical doctors. I once had an inspector of health security coming to a lab, asking to put a radioactive label near some stocks of D2O, 13C-glucose, 15N, 18O and so on)
1 liter of gasoline does not weight 1 kilogram, it's something around 0.75 kg, and the energy from 1 liter of gasoline burning is around 32 MJ on average
Dear Henry, what is a charge? Often we talk about subatomic particles having a positive or a negative charge (or no charge at all). But what exactly IS a charge and what's the difference between positive, negative, and neutral particles.
I guess gta wasn't aware of this
You're drivin' along, you're drivin' along, the kids start shouting from the back seat, "I gotta go to the bathroom, Daddy!" "Not now, damn it!" Truck tire. AHHHH, I CAN'T STOP!
I am a Stegassaurus
Nicely done. I didn't know that this was an advert. until the end! Loved it!
BeamNG.drive!!!
+Max Fuller eeeeeeeeXXXaaaaaccctly :D :D
i definetely support this channel and you . I like your videos
I just wanted to say good job on the video even if it is sponsored and sponsored content I think it was good thank you very much
Finally! Been waiting for a video for so long!
Guess you can now afFORD to make a video, huh?
+Seah Jia` En Gyan That was painful.
I need to send my parents this video lol. They still complain that cars nowadays are made out of outsourced garbage because they crumple and the old ones were so strong because they were made of steel. Man steel ain’t gonna absorb any of the impact 😂
same here, must be some news talking point or something, idk 🤣
is no one going to talk about how cool a sponsored video this is
HAHA funny how the thumbnail is a car running into a tree and talking about car Physics like paul walking hitting a tree he's the expert :')
#WATCHOUTFORTHATTREE!
Finally a good old hand drawn video :D
Wow, the stuff I didn't know. This is cool, and thank you for making it easy to understand.
i am a crash investigator. that was an awesome video. just like all of them. YEA science
I like the music! Great job, as always!
@0:08 1L Gasoline isn't eqaul to 1kg TNT in anyway.
a) Liter is an unit of volume (equal to 1 cubic decimetre)
b) Gram is an unit of mass
TNT and Gasoline do NOT have the density* of 1, so the comparison makes no sense.
(*density is mass (kg) per unit volume (L))
In terms of volume, it's equal. 1ml = 1cm2 = 1gram. Just change the unit 1L=1M 2(squared) = 1 kg
+TLK Dragon wow... no. just no. "1M 2(squared) = 1 kg" This is sooo wrong, that you must be a troll.
+TLK Dragon
We are not talking about water.
+Subjaeger i am pretty sure you don't understand what he is saying, he is talking about the energy that is release by those two things, what you are talking about has absolutely nothing to do with what he said.
Hey, can you do a video about treadmill running vs outdoor running? This debate with my friend will not end.
"Meticulously Engineered Destruction" sounds like an awesome metal song.
You can do an experiment like this with matchstick boxes.
Drop a matchstick box on the slidy end
Then open the box a bit and drop it again and notice the change
This was really cool. I love these videos.
DO The Physics of Skyding : like the energy from the speed of free fall and deceleration from the parachute opening and maybe more.
that would be awsome !
Should have featured a Model S crash pic, it's super cool.
LOL Just picked up my Ford today from the body shop after being rear ended about a month ago. Not much in the rear to absorb the energy on my little Ford Focus hatchback.
If you were wrapped in some kind of hard body casing would it keep your organs in place so you could survive very high G forces? I don't know a lot about this stuff. I heard a story once that a man fell from an airplane and his chute didn't open so he fell horizontally or flat and he survived because his organs didn't move very far, wheras if he had landed on his feet the organs could have separated and moved around easily.
Dear +MinutePhysics, any chance you could make an episode on Lagiewka Bumper?
What about the engine? What happens when it gets compressed in the car crash? (Given that the engine is in the front) Does it just turn off automatically? Or like in many games with cars, overheat and blow up?
Most cars are designed to push the engine down and out of the way as it crushes.
Those early cars also lacked seatbelts, which were forced on Fords by Robert MacNamara, who had observed their value during ww2, but he still screwed up the Vietnam war
You know, I feel so smart when watching your videos and pretending that I understand what you are talking about
Steel rails connected to the front bumper? Not in any modern car I've seen, unless he is referring to the bent sheet metal structure on either side of the engine compartment as a "rail"
Seatbelts also function to lengthen the time in takes you to become stationary. In addition to making sure you don't go flying out of the car!
It would be cool if you added this: How fast the car needs to be to a wheel come out when it crashes? Or a version about motorcycles.
Or, Physics of Plane Crashes, and other things related to vehicles.
I think i should commented in newer videos
I'm a Quality Engineer in the electronics industry. Trust me. Sudden stops are no better for robots than they are for humans, particularly since the advent of lead free solders. Ever wonder why your iPhone breaks when you drop it on the side walk? Same concept.
Is the figure of 56 megajoules of energy released by gasoline include the energy oxygen also releases when it combines with it chemically?
This is important when comparing to TNT because TNT releases all its energy by itself, not by combing with another chemical.
Wrong and wrong. No matter can release all their energy because they have a ton of that stuff and even uranium is very good at releasing good chunk of its energy and it only can give few % of it. Also TNT doesn't work all by its own
This answers a lot of questions I had for the past few months. But I have one more. Tesla has an empty front as the crumple zone, but since solid slows down collisions better than gas, why doesn't Tesla have like a giant spring in there or steel beams?
if it had a spring the car would bounce of and maybe fly into oncomming traffic, so its better that it crumples and then stays where it is
omai, you are back Henry! =D
0:43 when you cant draw an elephant but are a big fan of dinosaurs
You do the, relatively, simple physics lesson of elastic vs. inelastic collisions, if you haven't already. Also, if you don't feel it's below your pay-grade to do so.
what about military vehicles, like tanks travel at a high speed as well or those offroad vehicles where they do tricks like flying and jumping....just curious
I will recommend a video idea:The Bloop Mystery
While drawing deceleration curve did you take into consideration the air bag explosion??
One question, however, that has been driving me crazy for quite a few days is, why the fastest and more powerful cars have the lowest MPG? Would this mean that although high performance engines can deliver really high torque and horses it wastes way more fuel than their low end counterparts?
Examples:
Toyota Prius C 2016 -> 53 MPG in city
Ford Mustang GT 2015 -> up to 16 MPG in city
Bugatti Veyron 2011 -> 7 MPG in city
Average F1 car -> 3.1 MPG
Top Fuel Engine -> I couldn't find this but it can suck a full tank *of nitro methane* in just a 1/2 mile
How do you determine the force of impact if you know the velocity and mass of the car?
Good video!!
while i know this was uploaded to Vessel first.i do find it rather ironic since it is snowing like crazy in northern Utah, and i'm sure there will be plenty of accidents.