[HN Gopher] New world record with an electric racing car: From 0...
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       New world record with an electric racing car: From 0 to 100 in
       0.956 seconds
        
       Author : ldes
       Score  : 247 points
       Date   : 2023-09-12 15:14 UTC (7 hours ago)
        
 (HTM) web link (ethz.ch)
 (TXT) w3m dump (ethz.ch)
        
       | WirelessGigabit wrote:
       | Interesting video from Engineering Explained on the impact of
       | grip on acceleration: https://www.youtube.com/watch?v=i7yigpPSu_o
        
       | tromp wrote:
       | Particularly impressive considering the previous record stood at
       | 1.461 seconds! Few records get broken by such a huge margin...
        
       | alwaysrunning wrote:
       | As someone who grew up racing go karts and still enjoys motor
       | sports (mostly F1), the problem I have with e-racing is the lack
       | of sound. The winding noise they make just isn't adequate and
       | really puts me off to the racing.
        
         | onychomys wrote:
         | On the other hand, the Formula-E cars sound exactly like TIE
         | Fighters, and that's awesome.
        
         | chrsig wrote:
         | I'm sure there's some equivalent of putting a playing card into
         | the spokes
        
           | semi-extrinsic wrote:
           | Straight cut gears in the transfer case.
        
       | js2 wrote:
       | Impressive but for reference, about half the acceleration of a
       | Top Fuel dragster, which are also still getting faster.
       | 
       | Here's Brittany Force who holds the current records (fastest
       | time, fastest speed):
       | 
       | https://www.nhra.com/news/2022/brittany-force-sets-national-...
       | 
       | 0 to 338.43 mph in 3.665 seconds over 1000 feet. (The cars got
       | too fast for 1,320 feet and have been racing 1000 feet since
       | 2008.)
        
         | bluedino wrote:
         | 8G's max acceleration and -6G when they hit the brakes (using a
         | parachute)
         | 
         | 11,000hp!
        
         | epolanski wrote:
         | Aren't electric cars bound to beat any dragster car eventually?
         | You get max torque instantly.
        
           | xcv123 wrote:
           | Depends on how fast you can release that energy from the
           | batteries. Not as instant. Chemical explosions are rapid.
        
         | KennyBlanken wrote:
         | The dragsters need to have a complete engine tear-down after
         | nearly every run, regularly explode in a giant ball of flame,
         | etc.
        
           | 93po wrote:
           | I thought maybe this was a superficial tear-down but nope,
           | it's a whole heckin teardown and measurement of components
           | and relubing and cleaning and etc.
           | 
           | https://www.youtube.com/watch?v=I1RYmUxUqso
           | 
           | Also the end of this video gives an awesome perspective that
           | really shows the insane speed of these cars.
        
           | SoftTalker wrote:
           | They also blow a lot of that power out of the exhaust pipe. I
           | bet in terms of efficiency per km/h/s the electic go-kart
           | wins.
        
             | CarVac wrote:
             | The exhaust provides downforce though.
        
         | itishappy wrote:
         | Electric: 0-60mph in ~0.9s
         | 
         | Top Fuel: 0-60mph in ~0.4s
         | 
         | Wow.
        
           | westmeal wrote:
           | yeah top fuel is bonkers those engines literally eat
           | themselves alive down the track within milliseconds!
           | hardcore!!!!
        
           | rnk wrote:
           | Electric: 0-60mph in ~0.9s Top Fuel: 0-60mph in ~0.4s
           | 
           | That's students though, students at ~0.9s! Wow.
        
           | papa-whisky wrote:
           | I wonder if they'd go any faster if the rules allowed
           | overhead cams!
           | 
           | Even though these cars have disastrous efficiency and need to
           | be completely rebuilt after every run and have backwards
           | rules that leave them using "ancient" technology, I can't
           | help but be awed by the effectiveness of the sledgehammer
           | approach.
        
         | semanticc wrote:
         | I was sure you made a typo and meant 10000 feet, instead of
         | 1000. But after checking, yeah, it makes sense to make the
         | track shorter to avoid the cars reaching even more insane
         | speeds.
        
           | m463 wrote:
           | they've been playing this trick with top-fuel dragsters for
           | decades - the "speed" was measured far before the end of the
           | course. I think it was to keep the speeds below 300mph to
           | help with track insurance.
        
             | CodeWriter23 wrote:
             | They had a choice, lengthen drag strips everywhere or
             | decrease the length of the race. Because physics / braking
             | distance.
        
             | papa-whisky wrote:
             | I don't think it's a "trick", it's purely for safety
             | reasons. The distance change was made following a fatal
             | crash.
        
       | elmerfud wrote:
       | The impressive thing to me is the level of traction needed to do
       | something like this. It seems they're taking old tricks and
       | building a "sucker car".
       | 
       | https://www.roadandtrack.com/motorsports/a32350/jim-hall-cha...
       | 
       | Still neat stuff.
       | 
       | Race sanctioning bodies will need to update their rules or these
       | will just be one off bragging rights.
        
         | glax wrote:
         | Had the same thought, 0-100kmph in 3sec gives so much wheel
         | spin. Must be a whole lot of electronic trickery ever invented
         | from launch control, traction control to power management plus
         | the mechanical stuff sticky tyres, down force.
         | 
         | It amazes me how much faster we have got the last 6-7 years.
        
         | sokoloff wrote:
         | Fans (no pun intended) of sucker cars are likely to be
         | interested in the Goodwood record setting run by the McMurtry
         | Speirling car.
         | 
         | https://www.youtube.com/watch?v=5JYp9eGC3Cc
        
         | bborud wrote:
         | Then there's the Brabham BT46 "Fan car" that actually raced in
         | F1. Once. Before it was banned. :-)
         | 
         | https://youtu.be/B294RfWj1QE?si=jxYpIgwtH44at6Bq
        
           | raleec wrote:
           | ...and it's current spiritual successors The McLaren F1 and
           | now the GMA T.50 https://en.wikipedia.org/wiki/McLaren_F1
           | https://en.wikipedia.org/wiki/Gordon_Murray_Automotive_T.50
        
             | CarVac wrote:
             | From a Youtube interview with Gordon Murray I saw, the T.50
             | has fan-enhanced diffusers, the fan ingesting the boundary
             | layer to prevent flow separation.
             | 
             | It's not able to produce extra downforce at zero speed.
             | 
             | The McMurtry Speirling is more akin to this, with a 1.4s
             | 0-60mph run.
        
             | Nick87633 wrote:
             | Huh, never knew that the F1 had floor suckers!
        
           | emmelaich wrote:
           | Huh the Nick Mason credited with being a McLaren F1 owner is
           | the drummer from Pink Floyd.
        
             | ryukoposting wrote:
             | Suddenly I remember a Top Gear episode where Nick Mason
             | drops off his F1 (maybe it was a Ferrari Enzo?) at the test
             | track, then his personal helicopter lands on the strip,
             | picks him up, and flies him out of the scene, all while
             | "Money" by Pink Floyd plays in the background.
        
         | radicalbyte wrote:
         | In Micromouse (https://en.wikipedia.org/wiki/Micromouse) - a
         | competition where autonomous devices solve a mouse maze - the
         | fastest competitors are all using fans to increase traction
         | (and thus speed).
        
           | underlines wrote:
           | radicalbyte, you're absolutely right that the use of fans in
           | Micromouse increases the traction, and therefore the speed at
           | which the maze is solved. Suction allows for impressive
           | performances.
           | 
           | However, a small caveat that might be worth considering is
           | that while the suction indeed increases speed, it might be
           | more accurate to say that it primarily improves acceleration
           | instead of car speed: The issue often lies with achieving
           | rapid acceleration rather than with maintaining high speed.
           | Even systems with relatively low traction can reach high
           | speeds given enough time and distance, but the ability to
           | accelerate quickly is crucial in competitions like
           | Micromouse.
        
             | HPsquared wrote:
             | Speed = [?](acceleration) dt
        
               | epolanski wrote:
               | Exactly, thus you can simply integrate over a longer time
               | span.
               | 
               | But if you want to increase the acceleration you need
               | traction, your tyres need to be glued to the asphalt.
               | Since you don't have aerodynamic pressure at those speeds
               | you need to suck the vehicle to the ground.
        
               | westurner wrote:
               | Derivatives of relative displacement as defined by a
               | distance metric in a [e.g. metric tensor] space:
               | Length = Point2 - Point1       Length * Time^-1 =
               | Velocity or Speed       Length * Time^-2 = Acceleration
               | Length * Time^-3 = Jerk       Length * Time^-4 = Snap or
               | Jounce       Length * Time^-5 = Crackle       Length *
               | Time^-6 = Pop
               | 
               | Displacement (geometry) > Derivatives: https://en.wikiped
               | ia.org/wiki/Displacement_(geometry)#Deriva...
               | 
               | Fourth, fifth, and sixth derivatives of position: https:/
               | /en.wikipedia.org/wiki/Fourth,_fifth,_and_sixth_deriv...
        
               | anikan_vader wrote:
               | Sure, but once you have speed you can use aerodynamics to
               | get grip (e.g., F1 cars). So this is really only relevant
               | if you need acceleration from low speed.
        
             | hanniabu wrote:
             | > radicalbyte, you're absolutely right that the use of fans
             | in Micromouse increases the traction, and therefore the
             | speed at which the maze is solved. Suction allows for
             | impressive performances.
             | 
             | This reads like chatgpt
        
               | 0xDEF wrote:
               | So many old polite people on the Internet are going to be
               | accused of being AI chatbots.
        
           | chen_dev wrote:
           | Interesting topic. A pretty good video about this:
           | https://www.youtube.com/watch?v=ZMQbHMgK2rw
        
         | gladoskar wrote:
         | These cars stem from the Formula Student, which since 2022 has
         | re-allowed the previously forbidden "powered ground effect".
         | 
         | But this car has an upgraded battery and powertrain beyond what
         | the rules allow and they maybe also use tire warmers and
         | potentially rubber/glue on the launch surface/tires
        
         | sjburt wrote:
         | Interesting. This is a Formula Student car, the european
         | version of the Formula SAE. Powered ground effects were banned
         | a long time ago in Formula SAE, but it seems like Formula
         | Student does allow them.
        
           | gladoskar wrote:
           | It was disallowed for many years but is re-allowed since the
           | 2022 season
        
       | rfwhyte wrote:
       | I was expecting be disappointed when it was some kind of RC or
       | slot car type thing, but for a vehicle an actual human person
       | fits inside and controls, this is epically awesome.
        
       | londons_explore wrote:
       | I think hub motors like this are the future. Frees up space under
       | the car for more battery. Removes the complexity of drive shafts
       | and universal joints. Gives software full traction control.
       | Reduces design time for new vehicles (just route a power and data
       | cable to a wheel and you have a vehicle). Is the first step to
       | all-electric braking.
       | 
       | The downside is more unsprung mass. But modern motors are getting
       | lighter and lighter. And without a drive shaft, wheels could do
       | crazy things like moving in and out to avoid potholes, or
       | dynamically adjust camber to match the road you're on.
        
         | namdnay wrote:
         | Modern motors get lighter in part because they can offer lower
         | torque with a smaller rotor but compensate with higher rpm.
         | That's not possible for a hub motor
        
           | spixy wrote:
           | Can you compensate smaller rotor with larger stator (magnet),
           | so rpm could stay the same?
           | 
           | And why you cannot have small hub motor with high voltage
           | (kilovolts) and very high rpm?
        
       | xnx wrote:
       | Very cool, but also kind of impressive that a Tesla manages this
       | in ~2.5 seconds while doing all the other stuff a production car
       | does. What time would a Tesla get if you stripped out all the
       | extra weight? (seats, glass, electronics, roof, etc. etc.)
       | 
       | Video here (900 MB download):
       | https://polybox.ethz.ch/index.php/s/uKWFRcBjtl4foEy/download...
       | (couldn't find it on their YouTube page yet:
       | https://www.youtube.com/@AMZFormulaStudent/videos)
        
         | londons_explore wrote:
         | I'm pretty sure a Tesla spends most of its 2.5 seconds traction
         | limited. Ie. if you could fit gearwheels and drive on a toothed
         | road, I think a stock tesla could accelerate faster.
        
           | gregoriol wrote:
           | Or burn, or cost three times the price! Most components used
           | in Teslas are not made to run so intensively, wether it is
           | the wheels, the motors, the battery, the brakes, ... they
           | most likely limit the acceleration to prevent bad things.
        
         | tw04 wrote:
         | >What time would a Tesla get if you striped out all the extra
         | weight? (seats, glass, electronics, roof, etc. etc.)
         | 
         | That's been done - you don't actually want to remove things
         | like glass because the aerodynamic efficiency loss doesn't
         | outweigh the weight removal.
         | 
         | https://www.youtube.com/watch?v=ywvGbus3yxo
        
           | dave7 wrote:
           | There's still lots of extra weight on that Tesla! Take a look
           | at this one lol:
           | 
           | https://www.youtube.com/watch?v=z27t9uHp7nY
        
           | xnx wrote:
           | Neat! It looks like their 0-60 mph time was 1.37s.
        
             | zamadatix wrote:
             | Funnily enough, better than the previous world record
             | holder.
        
               | teachrdan wrote:
               | Not exactly -- the previous record was for 1 to 100, not
               | 1 to 60.
        
               | AntiRush wrote:
               | That's 0-100kph (0-62mph).
        
           | bluedino wrote:
           | What's the math on the weight vs the affect of drag at that
           | level? Aero doesn't come much into play in 0-60.
           | 
           | "Drag karts" are becoming a thing and they do just fine
        
         | m463 wrote:
         | Uh, Telsa plaid does 0-60 in 1.9 seconds
        
           | enragedcacti wrote:
           | The 1.99* that Tesla reports is a 0-60mph on a VHT prepped
           | surface (glue basically) with one foot of rollout deleted.
           | 
           | This is 0-100kph (0-62.1mph) on standard tarmac without any
           | rollout which a plaid does in about 2.5 seconds.
           | 
           | https://teslamotorsclub.com/tmc/threads/model-s-
           | plaid-0-100-...
        
         | [deleted]
        
         | bdcravens wrote:
         | Still wouldn't get close (in the performance sense, where the
         | effort to time gained is logarithmic in nature).
         | 
         | This car weighs 309 lbs. The batteries alone in a Model S
         | weight 1200 lbs.
        
           | linsomniac wrote:
           | True, but this car has low 300s HP, no torque mentioned that
           | I saw. The Tesla is over 1K HP and torques. The Teslas, for
           | road cars, are pretty stunning for acceleration. Agreed that
           | it's not going to reach this level of 0-100 performance, but
           | it sounds like it can get shockingly close.
           | 
           | I've driven Porsches on the track, and the Tesla Model S
           | Ludicrous loaner I had for a few days is startlingly fast.
           | Fast enough that I decided I was glad I didn't get one.
        
             | MrMan wrote:
             | [dead]
        
             | semi-extrinsic wrote:
             | This thing has a power to weight ratio of close to 2 HP per
             | kg. That is beyond insane, and if they didn't have active
             | suction that is essentially doubling the grip, this thing
             | would just be fast at converting rubber into smoke.
             | 
             | Just to put in perspective how ridiculous it is, the
             | equivalent would be if the Tesla was close to 5000 HP and
             | could produce 5000 lbs of suction downforce at standstill.
        
       | CodeL wrote:
       | Considering the rapid advancements in electric vehicle technology
       | and traction control, how will traditional metrics of automotive
       | performance evolve, and what new benchmarks will define the
       | supercars of the future?
        
       | mydriasis wrote:
       | Now _that_ is hot rodding. Can't wait to see what the drag strip
       | looks like in ten years!
        
         | adolph wrote:
         | I was thinking the same. It is interesting to think of
         | different fuel modalities. Liquid fuels seem to have a
         | throughput advantage for now. The article doesn't seem go into
         | electrical depth. From the pictures, it looks like they are
         | powering all four wheels at the hub.
         | 
         | This articles says" The vehicle weighs just 140 kilograms and
         | has an output of 326hp." https://www.swissinfo.ch/eng/swiss-
         | students-break-world-reco...
         | 
         |  _A top fuel dragster accelerates from a standstill to 100 mph
         | (160.9 km /h) in as little as 0.8 seconds (less than one third
         | the time required by a production Porsche 911 Turbo to reach 60
         | mph (96.6 km/h))[1] and can exceed 297 mph (478.0 km/h) in just
         | 660 feet (201.2 m). This subjects the driver to an average
         | acceleration of about 4.0 g0 (39 m/s2) over the duration of the
         | race and with a peak of over 5.6 g0 (55 m/s2)._
         | 
         | https://en.wikipedia.org/wiki/Top_Fuel
        
         | [deleted]
        
         | eimrine wrote:
         | 8-wheels or more and tons of batteries
        
           | sottol wrote:
           | ...and lithium fires.
           | 
           | Unfortunately, I think there will be pearl clutching and new
           | rules that allow gas/diesel powered vehicles only "due to
           | safety", at least my guess.
        
             | poniko wrote:
             | In ten years it's all going to be solid state, no more
             | fires.
        
               | sottol wrote:
               | I hope so!
        
               | sroussey wrote:
               | For sure, assuming we haven't switch from Lithium to
               | Aluminum by then.
        
             | gambiting wrote:
             | .....the what now? Have you watched any drag strip racing,
             | like, ever? Cars regularly go up in flames. The suggestion
             | that normal ICE cars would be allowed over EVs for "safety"
             | is actively hilarious.
        
               | sottol wrote:
               | Just the first example I could quickly find:
               | 
               | https://www.digitaltrends.com/cars/electric-cars-banned-
               | from...
               | 
               | Or
               | 
               | https://www.yellowbullet.com/threads/evs-got-banned-from-
               | rac...
               | 
               | And sounds like it's not for lithium fires only but also
               | traction control.
        
               | trashtester wrote:
               | I think you missed the point. For a petrolhead, a lithium
               | fire is like a nuclear fire for a Green Part voter in
               | Germany.
        
             | athorax wrote:
             | I highly doubt this. It is already a pretty regular
             | occurrence for ICE cars to combust on drag strips
        
               | mikeyouse wrote:
               | Yeah.. if people think the prospect of a lithium fire is
               | going to scare drag strips into banning them, even under
               | 'false' pretenses, they haven't spent any time at a drag
               | strip.
               | 
               | Most drag strips are run by volunteers or extremely small
               | hobbyist tracks and have almost no regard for safety.
               | Basically if the driver is wearing a helmet (and a fire
               | suit at more formal places) you can run it. To compete
               | they'll often require roll cages but most pulls are just
               | against the clock so on many nights they let any random
               | joe schmo pull up and get a time.
               | 
               | The crowd often line the lanes behind small concrete
               | barriers and people are usually welcome in the staging
               | area and right up next to the burnout boxes..
               | 
               | Explosions and fires are common, as are crashes.
               | 
               | https://youtu.be/O7P_2voFMRE?t=35
               | 
               | https://youtu.be/QeIwAJK3iBg?t=128
        
               | sottol wrote:
               | Maybe it's the traction control then
               | 
               | https://www.yellowbullet.com/threads/evs-got-banned-from-
               | rac...
        
             | orangepurple wrote:
             | Drag racers used to use hydrazine which would slowly
             | convert into a contact explosive when mixed with gasoline.
             | The exhaust flames were green. If the carburetor and fuel
             | tank was not purged fast enough after a race the engine,
             | carb, and/or fuel tank would explode and sometimes kill
             | people. I doubt drag racers or venues are scared of
             | lithium.
        
           | jansan wrote:
           | Remember the six wheeled Tyrrell P34 F1 racing car?
           | Admittedly, ony the rear axis was driven, but that was one
           | badass car (and it won a Grand Prix).
           | 
           | https://en.wikipedia.org/wiki/Tyrrell_P34
        
             | cromulent wrote:
             | Yeah it was unforgettable. Also the Williams FW08B, but
             | that was banned before racing.
             | 
             | https://www.motorsport.com/f1/news/six-wheeled-formula-
             | one-w...
        
       | briandear wrote:
       | A Ducati MotoGP bike does it in 2.3 seconds just as a point of
       | reference.
        
       | mrob wrote:
       | Interesting that they went with an open-cockpit design. I'd have
       | thought closed cockpit would be faster because of better
       | aerodynamics, even at these relatively low speeds. Any idea why
       | this was chosen?
        
         | Saturn5 wrote:
         | This is the typical design for the competition this car was
         | originally build for. The rules of Formula Student require an
         | open cockpit with a hoop, and you have to demonstrate that your
         | driver is able to egress within 2(?) seconds if I remember
         | correctly.
         | 
         | This record was set with a modified version the car they
         | competed with last season.
        
         | kukkamario wrote:
         | I'm guessing weight is more important than aerodynamics if
         | target is 0-100km/h.
        
       | omginternets wrote:
       | Jesus, do you need a G-suit??
        
         | rgmerk wrote:
         | Nah, impressive as it is, if you've ever ridden a roller
         | coaster you'll have experienced forces greater than this.
        
       | mattferderer wrote:
       | Out of curiosity, what's the point of a driver in something like
       | this besides to have a human in the vehicle adding weight? Are
       | they doing much?
       | 
       | Serious & maybe very ignorant question.
       | 
       | - Edit - For clarification, my reason for asking was due to this
       | occurring in less than 1 second. I don't understand what the
       | driver does as I'm assuming they have no gears to shift or turns
       | to make.
        
         | lazide wrote:
         | Raises the stakes, provides a degree of accountability.
         | 
         | Otherwise it's just a missle with a required degree of ground
         | contact, no?
        
         | xwowsersx wrote:
         | I assume it's because racing, as a sport, is a lot less
         | interesting without the variable of a human with particular
         | skills operating the vehicle. I doubt crowds would be as
         | interested in watching cars race on autopilot, though it'd
         | still be kind of cool, I guess.
        
           | madamelic wrote:
           | > racing, as a sport, is a lot less interesting without the
           | variable of a human with particular skills operating the
           | vehicle.
           | 
           | If full self-driving gets much better, I think it could be
           | fun to see this happen. It would be like a hackathon with
           | teams swapping out and improving on strategies through laps.
           | The qualifiers could happen on electric miniatures then the
           | final round would get a full car to race on a track.
        
             | xwowsersx wrote:
             | That actually does sound pretty fun haha
        
             | dpkirchner wrote:
             | I think a fully automated battlebots arena might be more
             | fun but I'd still watch track racing.
        
             | gladoskar wrote:
             | The racing formula this is from, Formula Student, actually
             | has a driverless competition as part of it. It's pretty
             | fun, but also harder than one would think, still.
        
         | wincy wrote:
         | I'd hazard you can't get a world record without a human being
         | in the car?
         | 
         | I'm no mechanical engineer, but I could definitely make
         | something without a human inside of it go from 0-100 in less
         | than a second.
        
           | itishappy wrote:
           | A bullet will do 0-60mph in 20ms.
        
           | xwdv wrote:
           | Definitely could do it in sub 0.2 seconds quite easily.
        
         | sillysaurusx wrote:
         | Fair question. But ultimately human sports are about humans.
         | It's just less exciting to watch robots compete (though I like
         | it).
        
         | dfxm12 wrote:
         | Guinness world records are well defined and some are kinda
         | arbitrary. In some sense, I'm sure the driver is there to
         | satisfy the rules of the world record. In another sense, I'm
         | sure they're there to have a load of fun, too.
        
         | gladoskar wrote:
         | AMZ's cars are also capable of autonomous driving (they were
         | actually one of the top teams in the autonomous categories for
         | the last couple of years).
         | 
         | I assume it's just a requirement for this Guiness record
         | category, or they didn't want to bother with all the software.
        
       | hersko wrote:
       | 100kmh, not mph.
        
       | lifeisstillgood wrote:
       | One of the photos really brought something home to me. Where I
       | would expect to see an axle or something to provide torque to
       | wheels from the engine, there is just a yellow wire.
       | 
       | I _know_ that 's how electric cars work. But something about it
       | in the racing car context just brings it home to me - electricity
       | just works differently to all our other intuitions about the
       | world. Factories used to have bands and axels taking power from
       | one central steam engine to all corners of the building. And then
       | they got redesigned once electricity came in.
       | 
       | I got a gut realisation from that photo that something similar is
       | / has happened.
       | 
       | I like to emphasise using "boring tech" at work to avoid chasing
       | too many rainbows. But sometimes there is a pot of gold and I
       | need to remember that, else my factory will remain steam powered.
        
         | 1-more wrote:
         | > Factories used to have bands and axels taking power from one
         | central steam engine to all corners of the building.
         | 
         | From my own experience: a popular home woodworker tool from the
         | middle of the 20th century is a Shop Smith. It had a motor that
         | you would couple to the various mounted attachments to run the
         | lathe or the band saw or the table saw etc one tool at a time.
         | I guess part of the appeal was certainly the size savings, but
         | I have to think it was also only having to buy one electric
         | motor. Life changingly good motors are now commodity parts, and
         | artisanally crafted ones are setting acceleration world
         | records. Cool time to be alive.
        
           | munificent wrote:
           | Tractors, still widely used today, as essentially a mobile
           | version of this.
           | 
           | One of the main purposes of a tractor, compared to other farm
           | vehicles, is that it has a power take-off [0] to enable the
           | engine to drive other farm implements like combines.
           | 
           | [0]: https://en.wikipedia.org/wiki/Power_take-off
        
             | pests wrote:
             | I've never actually thought about what a tractor actually
             | is. I've seen them in use and could roughly describe one
             | but its actual purpose or intent was unknown to me until
             | now.
        
         | mdorazio wrote:
         | Kind of. This team is specifically using hub motors, thus
         | bypassing the need for traditional axles. Hub motors are
         | notoriously inefficient, though, so you don't see them in
         | normal BEVs which typically mount the motors near the center of
         | the axle (as part of an "e-axle"). Basically, this team's car
         | is purpose built only for acceleration and thus gets away with
         | doing things you wouldn't see in cars that need to maintain
         | speed or drive efficiently. Great ingenuity by them!
        
           | toss1 wrote:
           | YES
           | 
           | The use of hub motors is probably best when acceleration is
           | paramount, but when handling starts to come into play (e.g.,
           | on road courses), it is likely best to bring the motors
           | inboard and spend the extra weight and complexity of axles,
           | as the unsprung weight outboard of the suspension is a
           | serious detriment to handling.
        
           | tromp wrote:
           | They needn't be inefficient, as demonstrated by their use in
           | the hyper efficient Lightyear0 solar powered car. But they do
           | have plenty downsides [1].
           | 
           | [1] https://evcentral.com.au/why-dont-evs-have-four-in-wheel-
           | mot...
        
         | mannyv wrote:
         | Yeah, they've taken the "distribute mechanical work" part out
         | of the process.
         | 
         | It's amazing that all those car cylinders going up and down (or
         | technically, being forced up and down by tiny explosions) are
         | transformed into work.
         | 
         | Rotary motion -> work has been part of humanity for a long
         | time. I suppose in our space-bound future it won't be a big
         | factor
        
           | imoverclocked wrote:
           | Except as artificial gravity or pumps or geared robotic arms
           | or automatic doors or ... I think we'll have rotary motion
           | for some time to come.
        
       | expertentipp wrote:
       | How many football fields of acceleration is this?
        
         | stuff4ben wrote:
         | American or rest-of-the-world football?
        
           | ozr wrote:
           | Football, not soccer, of course.
        
             | bborud wrote:
             | Oh, you mean handegg :-)
             | 
             | https://br.ifunny.co/picture/ag-not-soccer-not-football-
             | it-s...
        
           | [deleted]
        
         | LanceH wrote:
         | American or Canadian?
        
         | jaclaz wrote:
         | Since it is 12.3 meters a more suitable unit of measure (for US
         | journalists) should be the schoolbus.
        
         | perihelions wrote:
         | It's *roughly* the gravitational acceleration at the surface of
         | an Olympic-size swimming pool of electron-degenerate matter
         | from a white dwarf star. Hope this helps!
         | 
         | (Note: the swimming pool has collapsed under its own weight and
         | is now a sphere).
        
           | lucgommans wrote:
           | A white dwarf's density is apparently around 1e9 kg/m3.
           | Olympic swimming pools at 50m*25m*2m * 1e9kg/m3 would have a
           | weight of 2.5e12 kg. As a sphere, the radius is (solving:
           | volume_of_sphere = 4/3xpxradius3)                   $ qalc
           | 50m*25m*2m = 4/3*pi*x^3         (((50 * meter) * (25 * meter)
           | * (2 * meter)) = ((4 / 3) * pi * (x^3))) =         approx. (x
           | = 8.4194515 m)
           | 
           | Gravitational acceleration (for a point mass) is: the
           | gravitational constant, multiplied by the mass, divided by
           | the radius squared, and we want the result in Earth
           | gravities:                   $ qalc G * 2.5e12kg / 8.41945152
           | m2 to gee         (newtonian_constant * ((2.5 * (10^12)) *
           | kilogram)) / ((8.4194515^2) * (meter^2)) =         approx.
           | 0.24 gee
           | 
           | You're only one order of magnitude off -- if this is correct,
           | which I am really not sure about!
           | 
           | Sources: https://en.wikipedia.org/wiki/White_dwarf *
           | https://en.wikipedia.org/wiki/Olympic-size_swimming_pool *
           | https://duckduckgo.com/?q=volume+of+a+sphere&ia=answer * http
           | s://www.wolframalpha.com/input?i=surface+gravity+calcula...
           | 
           | What I'm even less sure how to calculate is whether an
           | 8-meter sphere can be that heavy. Uranium is ~2e4 kg/m3, but
           | under its own gravity, things shrink until they reach black
           | hole status (infinite smallness; perceived size coming from
           | its event horizon). Basically I'd want to turn the above
           | 1e9kg/m3 into an unknown, but what's the formula for mass
           | given your specified radius and gravitational acceleration?
           | TBD
           | 
           | I'm really curious if this was just a few words strung
           | together and it happened to come out to within one order of
           | magnitude by pure coincidence, or if (how) you calculated
           | this!
        
             | perihelions wrote:
             | - _" You 're only one order of magnitude off_"
             | 
             | Oh shit you're right. Root cause: I saw "3 g" and wrote "3
             | m/s^2".
        
               | lucgommans wrote:
               | :D
               | 
               | What calculation did you use though? Like some formula or
               | is there a web utility for this, for example?
        
               | perihelions wrote:
               | https://www.google.com/search?q=3+m%2Fs%5E2+%2F+%28gravit
               | ati...
               | 
               | I think
        
               | lucgommans wrote:
               | I don't understand, is that what you used originally to
               | come up with your original comment (this one:
               | https://news.ycombinator.com/item?id=37483892)?
               | 
               | If so, that is surprisingly similar to what I ended up
               | with when trying to validate it!
        
         | elboru wrote:
         | At least 2
        
         | uberman wrote:
         | about 0.11 football fields were required to reach 100km/h
        
           | hedora wrote:
           | That seems high. What was the mass-to-energy conversion
           | efficiency?
        
             | uberman wrote:
             | 13.5 yards to go from 0 to 60mph seems high? How far did
             | you anticipate it would take to reach that speed?
        
       | elromulous wrote:
       | Is this for some kind of [European?] [electric?] Formula SAE
       | equivalent?
       | 
       | I took part in formula SAE ~20 years ago! Some of the first and
       | most rewarding engineering work I've done.
        
         | thedrbrian wrote:
         | Yes but you ignore the bit where you're making a car affordable
         | to the common man
        
         | ihunter2839 wrote:
         | Yes, or maybe more accurately - we are the American equivalent
         | of Formula SAE Germany. The German teams are significantly more
         | advanced and better funded, with some of the teams running
         | custom built electric inhub motors (something that's unheard of
         | here in the US)
         | 
         | I am currently on San Jose States Formula SAE team - we merged
         | our electric and combustion teams last year to go all electric
         | since it's where the stiffest competition exists. If we could
         | secure sponsorships we'd love to take our car to Germany!
        
           | no_wizard wrote:
           | I didn't know San Jose State had enough money to run an team
           | like this.
           | 
           | Unless I'm mistaken, aren't Formula teams expensive? the cars
           | get rebuilt often, I imagine its no different with electric
           | (less to rebuild, perhaps, but anything mechanical would need
           | to be)
           | 
           | Thats awesome though!
        
             | gladoskar wrote:
             | It's definitely expensive, and sponsor aquisition is always
             | a success factor as in every racing league.
        
           | consp wrote:
           | Formula Student Germany has been leading the rules for the
           | electric and driverless since their inception. There is a
           | meeting every few years at the FSG event to align some rules
           | for the different global student competitions. There was one
           | this year again. (Source: I'm in the timekeeping
           | team/organisation, to the driverless cars: please stop
           | destroying our gear)
        
       | tsunamifury wrote:
       | On a related note in the sports car community its been
       | interesting to watch Acceleration stop being a mark of a
       | performance car. There is even a lot of chatter around this being
       | the end of the supercar segment since there are family wagons
       | that can now do 2 second 0-60 runs. On top of that the speed is
       | now too much for anyone to reasonably use off a drag strip or
       | circuit.
       | 
       | Now there is a huge emphasis on engagement, dynamics, and a bunch
       | of vague "feelsomeness" as sports cars slowly become like horses.
       | 
       | The march of time is interesting...
        
         | AtlasBarfed wrote:
         | Strangely, acceleration seem to stop mattering when EVs took it
         | over.
         | 
         | Suddenly, ICE heads started extolling the sensory virtues of
         | the combustion engine.
        
         | jansan wrote:
         | Acceleration was never really the top metric for super cars. It
         | was more performance at high speeds, with high end cars like
         | the Bugatti Chiron Supersport 300+ going up to 489 kmph (that
         | is a lot in case you wonder). Part of the super car segment
         | will go electric, that is for sure, but I do not see the end of
         | the super car. Look at luxury watches. They are booming despite
         | a Casio GShock with Multiband beating the shit out of them in
         | terms of accuracy.
        
           | tsunamifury wrote:
           | Super car segment is well below Bugatti. Thats a 2.5 million
           | dollar car. Super cars are between 150k usedish and a
           | million. Plus a lot of other vague definitions. Most people
           | say call the 911 the dividing line of a supercar and top of
           | the sports car range.
           | 
           | In general this segment is dying off, chasis are being reused
           | for 10+ years in the market, tons and tons of special edition
           | and reissues. most of the new work is being done in the
           | Hypercar segment which is almost just a nonsensical money-
           | fight space. And they were, for the most part, defined by
           | speed in the public eye. If you wanted feelsome-ness you just
           | go a Cayman or a Lotus.
        
             | jansan wrote:
             | I stand corrected, the Bugatti is a hypercar. It's a bit
             | embarrassing considering that I was in the workshop where
             | they make the Bugatti engines just a few weeks ago. Awesome
             | experience btw, seems to be part of the standard factory
             | tour at Volkswagen Salzgitter currently.
        
         | adfiognionio wrote:
         | This is really quite wrong.
         | 
         | Performance car /= sports car. Sports cars are light and nimble
         | by definition. They are usually fast, but this is not a rule.
         | There have always been sedans that are faster in a straight
         | line than most sports cars. There have always been sports cars
         | that are not very fast at all. None of this is new, and
         | claiming otherwise is ahistorical. Even back in the '60s, a
         | sports car enthusiast would have chosen an MGB over a much
         | faster Camaro, because the MGB is a sports car and the Camaro
         | is not.
         | 
         | Engagement, dynamics, and "feelsomeness" are not vague at all.
         | Handling is the product of engineering. It is largely
         | objective. Some cars really are easier to control than others.
         | Some really do hold on better in the corners. Cars really do
         | have more or less body roll and more or less oversteer. What
         | "character" is best is a matter of opinion, but the car really
         | does have that "character". The fact that something is hard to
         | measure does not mean it doesn't exist.
         | 
         | Sports car fans mean exactly what they say: they value handling
         | over acceleration. If they didn't mean it, they wouldn't buy
         | sports cars.
        
           | AtlasBarfed wrote:
           | And the Tesla plaid is the fastest nurburgring sedan ever
           | made.
           | 
           | Go ahead, say that's not a sports car.
        
             | timc3 wrote:
             | Its not a sports car. Besides, BMW M4 CSL, Jaguar XE
             | project 8, BMW M3, Mercedes AMG 63 GT have faster lap
             | times.
        
             | decafninja wrote:
             | If Nurburgring times are all we're looking at, there are
             | SUVs (ok, CUVs) that will destroy the times of "real sports
             | cars".
        
           | tsunamifury wrote:
           | [flagged]
        
             | adfiognionio wrote:
             | [flagged]
        
               | tsunamifury wrote:
               | Again, read your own statements here and think about who
               | you want to be. Why be such a angry person on a forum
               | where nothing matters...
        
         | jbm wrote:
         | We see this same sentiment in comments on this very website.
         | Comments like "Straight line acceleration doesn't matter", for
         | example.
         | 
         | Except, as a driver, I never accelerate in a tight curve. Once
         | I got an EV, aggressive drivers were no longer able to block me
         | from merging into traffic; if anything, I was able to easily
         | get away from them if necessary.
         | 
         | I believe what we are seeing is car enthusiasm being pushed
         | further into the long tail. Aesthetics, self-sufficiency
         | through repair, exotics, etc, will always have a place, but
         | speed off-track is over. ("Drive feel" is the new "gold cable
         | connectors".)
        
           | tsunamifury wrote:
           | The majority of the long-tail is just becoming "its really
           | expensive" and "its an investment asset" unfortunately.
        
         | enragedcacti wrote:
         | > Now there is a huge emphasis on engagement, dynamics, and a
         | bunch of vague "feelsomeness" as sports cars slowly become like
         | horses.
         | 
         | I think this is mostly just the experience of people who only
         | started caring about performance cars when EVs started being
         | competitive. Porsche people (and many others) have been ranting
         | about the engagement and driving dynamics for 50 years now.
         | There are decades of arguments on forums about handling, 50/50
         | weight ratios, understeer and oversteer, shifter feel, track
         | times, etc. in addition to arguing about straight line
         | acceleration.
         | 
         | EV people feel like those things are just excuses because
         | previously they only digested mainstream auto news which puts a
         | massive emphasis on straight line acceleration.
        
           | tsunamifury wrote:
           | This has been an age old debate -- if you read the comment
           | closely it was saying that supercars were defined by
           | acceleration and handling, but now acceleration is no longer
           | their forte. You could always get a sports car like a P-car
           | if you wanted handling.
           | 
           | Don't think everything is just defined by this one issue, it
           | goes way back, but Electric has now killed the first half of
           | a supercar
        
             | enragedcacti wrote:
             | > if you read the comment closely it was saying that
             | supercars were defined by acceleration and handling
             | 
             | > _sports car_ community
             | 
             | > as _sports cars_ slowly become like horses
             | 
             | can you see how I might have been confused that the comment
             | was about sports cars?
             | 
             | > supercars were defined by acceleration and handling, but
             | now acceleration is no longer their forte.
             | 
             | I would argue that their forte is (usually) being fast
             | around a track, and that acceleration and handling are just
             | aspects of a complete system, subject to engineering
             | tradeoffs like anything else. When we evaluate through that
             | lens, ICE/hybrid supercars are doing just fine.
        
         | [deleted]
        
         | wing-_-nuts wrote:
         | Honestly I'd bet that anything at or below a 9s 1/4 mile is
         | physically painful. It's gotta feel like getting thrown into a
         | padded wall.
        
       | 11235813213455 wrote:
       | if it was 100m in that time, it would be almost exactly 10 times
       | faster than Usain Bolt
        
       | diziet wrote:
       | I am curious what sort of physical preparation the driver (Kate
       | Maggetti) did to train for these runs, if any? Surprisingly the
       | average g-force is just under 3 g.
        
         | [deleted]
        
         | tim333 wrote:
         | Not sure but it's fairly mild compared to what I think is the
         | fastest accelerating car, Sammy Miller's Vanishing point which
         | I think recorded 26g. They had some failsafe to stop the car if
         | he passed out on that one. (car doing a 3.22 quarter
         | https://youtu.be/7QC6tymIvKA?t=213)
        
       | hprotagonist wrote:
       | how many gees is that?
        
         | mherrmann wrote:
         | 3, as in "omg".
        
         | tzot wrote:
         | $ units         You have: 100 km per hour / 0.956 sec
         | You want: gravity             * 2.9629132             /
         | 0.33750567
        
           | lucgommans wrote:
           | Protip: no need for a dedicated unit conversions utility,
           | this awesome calculator has it built in:                   $
           | apt install qalc         $ qalc         > 100 km/h / 0.956 s
           | to gee           (100 * (kilometer / hour)) / (0.956 *
           | second) =           approx. 2.9629132 gees
        
         | BizarroLand wrote:
         | About 2.96gs.
         | 
         | Using https://rechneronline.de/g-acceleration/, going from 0 to
         | 100 km/h in .956 seconds says it is 2.96gs of acceleration.
        
         | nickcw wrote:
         | Python says this for 0 to 100 kph in 0.956s
         | >>> 100*1000/3600/0.956/9.81         2.961901417494933
         | 
         | So just about 3 standard Earth gravities!
         | 
         | This assumes uniform acceleration which isn't likely so that is
         | the average.
        
       | csours wrote:
       | > "To ensure strong traction right from the start, the AMZ team
       | has developed a kind of vacuum cleaner that holds the vehicle
       | down to the ground by suction."
       | 
       | Traction is now the limiting factor, so better acceleration
       | results will be driven (hah) by better traction.
        
         | TremendousJudge wrote:
         | A similar thing was done in F1 in 1978:
         | https://en.wikipedia.org/wiki/Brabham_BT46
         | 
         | It was swiftly banned of course, since it worked too well.
        
         | ActorNightly wrote:
         | Traction has always been the limiting factor in automotive
         | performance.
         | 
         | There is a reason why a Civic Type R set a faster time than
         | exotic cars of early 2010s, and thats because modern street
         | tire compounds are as grippy as slick racing tires from those
         | years. And now, race tires have a static friction coefficient
         | greater than 1, because when warmed up they actually glue
         | themselves to the road.
        
           | csours wrote:
           | At this level, yes. For the family sedan, ehhh.
        
       | jasonjmcghee wrote:
       | 100 km/h, to remove any ambiguity
        
         | KingOfCoders wrote:
         | Thanks, my first thought was 100x the airspeed velocity of an
         | unladen swallow.
        
           | vondur wrote:
           | African or European?
        
           | ru552 wrote:
           | mine was miles
        
           | [deleted]
        
           | [deleted]
        
         | rob74 wrote:
         | Yeah, "0 to 100" is so commonplace in Europe that even the
         | engineers from ETH Zurich leave out the units.
         | 
         | Reminds me of being asked in the US what the fuel consumption
         | of our car was (in miles per gallon) and not being able to
         | answer because the usual unit in Europe is liters per 100 km
         | (didn't have a smartphone back then).
        
           | chungy wrote:
           | "0 to 60" is likewise so common place in America that we
           | often leave out the units (mph).
           | 
           | It's probably obvious enough in the car context which unit is
           | being talked about, between 0-60 and 0-100.
        
         | [deleted]
        
       | enragedcacti wrote:
       | I find the suspension design to be really interesting. It seems
       | like the front wheels and the rear wheels each share a single
       | coilover and they use hydraulic cylinders at each wheel to
       | transmit the force. I'm sure this saves a lot of weight but I'm
       | interested in how the suspension dynamics are changed by two
       | independent wheels sharing the same spring and damper.
       | 
       | Do any other vehicles do this? Are there are any other
       | applications where it would make sense?
        
         | gladoskar wrote:
         | This is actually fairly common in Formula Student cars. They
         | often use decoupled heave/roll suspension systems, where one
         | spring/damper is for the heave of the entire axle and another
         | one for the roll on the axle. It has some advantages over
         | separate springs, but I'd have to ask our suspension guys.
         | 
         | The graphics in this article show its function fairly well, but
         | don't explain the calculations either
         | 
         | https://www.marekdostal.com/suspension-design/
         | 
         | Recently, some teams have added the hydraulic relocation of
         | dampers, and some (like Dresden) even have software control of
         | them.
        
           | Nick87633 wrote:
           | Isn't the go-kart suspension still somewhat competitive,
           | though? I'd heard of teams that have suspension travel for
           | passing tech and then jack up the rates afterward.
        
             | gladoskar wrote:
             | Yes and yes
        
       | onnnon wrote:
       | You can watch the video on ETH Zurich's YouTube channel:
       | 
       | https://www.youtube.com/watch?v=mvoFemftA34
        
       | sova wrote:
       | km/h
        
       | queuebert wrote:
       | Weird, I was not expecting it to be basically a Formula SAE car.
        
       | KerryJones wrote:
       | The title should mention 100kmh, not mph
        
         | jansan wrote:
         | Or say it was done in Switzerland, that would make things
         | clear, too.
        
           | Symbiote wrote:
           | It does, the domain shown after the title is eth.ch.
        
           | [deleted]
        
           | snovv_crash wrote:
           | The domain name is ethz.ch, even if you don't know about ETH
           | Zurich the .ch will tell you it's Switzerland.
        
       | pedalpete wrote:
       | I was wondering how this compared to motorcycles, and didn't
       | realize that today's production motorcycles are not significantly
       | faster than modern hypercars, the fastest motocycle clocking in
       | at 2.2 seconds [1]
       | 
       | Ignoring the million dollar sports cars, other cars such as
       | Porsche 911 turbo s from 2020 is 2.1s.[2].
       | 
       | I know, Tesla and Lucid, etc are also crazy fast, but I believe
       | their quoted 0-60 times are all with a roll-out.
       | 
       | [1]https://en.wikipedia.org/wiki/List_of_fastest_production_mot..
       | .
       | 
       | [2]https://en.wikipedia.org/wiki/List_of_fastest_production_car..
       | .
        
         | tstrimple wrote:
         | Cars designed for high speed will have a significant advantage
         | over a motorcycle through capturing down forces to dramatically
         | increase the amount of friction between the tires and the
         | surface before losing grip and spinning out. Motorcycles can
         | own the power to weight ratio category, but they can't use all
         | that power because at that point the wheels just spin.
         | 
         | I found it super interesting when I learned that one of the
         | biggest advances in maze solving races is that someone ended up
         | putting a fan in their little "mouse" to push down so the
         | wheels could get more traction.
         | 
         | https://hackaday.com/2008/11/26/vacuum-micromouse/
         | 
         | More details on maze racing from Veritasium:
         | https://www.youtube.com/watch?v=ZMQbHMgK2rw
        
       | cogman10 wrote:
       | Could we maybe change the title here and change it to 100mph?
       | 
       | I realize this is the original article title but EV + 0 to 100
       | led me to believe the article was talking about battery charging
       | speed.
        
         | beAbU wrote:
         | 0 to 100% fully charged in less than one second?
        
           | LanceH wrote:
           | That sounds a lot more dangerous than 0 to 100km/h.
        
             | trashtester wrote:
             | It sounds like a capacitor.
        
           | pizzafeelsright wrote:
           | Nah, this thing is electrical. And in order to get that kind
           | of power you're going to need plutonium.
        
         | tekla wrote:
         | Who the hell would think that a 1s battery charging time with a
         | racing car would make any sense at all?
        
           | hedora wrote:
           | Pit stop times matter, and supercapacitors exist.
           | 
           | I'd love to watch that race, especially if the cars were
           | sucker cars like the one in the article, and the drivers got
           | to wear high-G fighter jet suits.
           | 
           | The best supercapacitors apparently have 20x the energy
           | density of the best batteries. Apparently, self-discharge can
           | be as low as 20% per day, which rounds to zero for racing.
           | They only cost 10x more than lithium batteries, which again,
           | for racing rounds to zero. Discharge current blows lithium-
           | ion so far out of the water that I couldn't find a rule of
           | thumb ratio.
           | 
           | https://supercaptech.com/battery-vs-supercapacitor/
           | 
           | edit: I had the energy density backwards; supercapacitors are
           | at 10% the density of lithium ion. Still, the other
           | advantages stand. I wonder how hard it would be to add an
           | inductive charger to a straightaway...
        
             | trashtester wrote:
             | > Pit stop times matter, and supercapacitors exist.
             | 
             | Imagine a pit "stop", where you keep your speed to
             | 300km/h/200mph, and you have your on-board supercapacitor
             | charged in 1 second, using a power transfer system borrowed
             | from electric trains.
        
             | timerol wrote:
             | > The energy density rating of the average supercapacitor
             | is between 2,500 Wh per kg and 45,000 Wh per kg.
             | 
             | That's from your source, and those numbers are entirely
             | made up. The Wikipedia article for supercapacitors lists a
             | more normal 1.5 Wh/kg to 260 Wh/kg (with only one research
             | nanomaterial going above 15 Wh/kg). No commercial
             | supercapacitor has a higher energy density than a standard
             | lithium ion battery.
             | 
             | Edit: The absurdly fast charging speeds would make for some
             | fun pit stops, though
        
         | ticklemyelmo wrote:
         | But 100mph (or kph) is also a way to describe charging speed.
        
         | sh1mmer wrote:
         | It's 100kph
        
       | pcurve wrote:
       | For those wondering it's g force of 2.95G.
        
       | chrisweekly wrote:
       | It shouldn't matter, but I'm personally delighted that the driver
       | was female.
        
         | moonchrome wrote:
         | Did you just assume their gender ?
        
           | Biganon wrote:
           | Oh looks this brilliant joke is now on HN as well, great
        
           | chrisweekly wrote:
           | No. Her name is Kate, and there's a photograph.
        
       | btbuildem wrote:
       | That's almost 3Gs of acceleration. Impressive!
        
         | cocoa19 wrote:
         | So the same as the Gravitron amusement ride popular in fairs
        
         | maerF0x0 wrote:
         | i used this calculator[1]. Looks like 3.5 . Just for fun...
         | Now, if we use the forces that air pilots can sustain for 2
         | seconds we're looking at about 0.35 seconds is around the
         | limit. and 0.3 seconds would create about 11Gs enough to kill
         | you (all according to quick googles of numbers.
         | 
         | If they can get a car to do 9Gs for 2 seconds we're looking at
         | about 635Km/hr !!
        
           | semi-extrinsic wrote:
           | 11G is not lethal for the short durations you need for 0-100
           | (or even 0-200).
           | 
           | A typical car crash at 20 mph is around 20 G deceleration.
           | 
           | If you look at racing car crash data, one study reports 50 G
           | as approximately the threshold for when you start to see
           | frequent brain injuries.
           | 
           | https://pubmed.ncbi.nlm.nih.gov/16531891/
        
         | rob74 wrote:
         | Thanks! I was about to ask how many Gs this translates too, my
         | physics are a bit rusty...
        
           | mrb wrote:
           | In GNU units you can just do:                 $ units -t '100
           | kph / (.956s) / gravity'       2.9629132
        
             | world2vec wrote:
             | TIL!
        
             | rjmunro wrote:
             | That query works in Wolfram Alpha too: https://www.wolframa
             | lpha.com/input?i=100+kph+%2F+%28.956s%29...
        
             | lucgommans wrote:
             | Rather than teaching a separate utility, I would recommend
             | qalc which has unit conversions built in :)
             | $ qalc -t 100km/h / 0.956s to gee         2.9629132 gees
             | 
             | (where -t is for terse mode; by default it expands unit
             | abbreviations and adds parentheses so you see whether it
             | did what you wanted)
             | 
             | The reason I recommend it is because it does so much more,
             | I really love this utility since discovering it about a
             | year ago. Example of using time notation combined with
             | uncertainty and unit conversion:                   > (18:41
             | - 09:00+/-00:30) hours * 250 W to kWh           (((1121 /
             | 60) - (9+-0.5)) * hour) * (250 * watt) =           approx.
             | (2.4208333+-0.125) kW*h
        
               | chungy wrote:
               | The irony of advocating against a "separate utility", and
               | then promoting a separate utility...
        
               | lucgommans wrote:
               | You never use a calculator?
        
               | chungy wrote:
               | I use calculators plenty, but I neither have that one
               | installed nor use it. On my PC, I use either grpn or
               | units. More often, I pull out my HP 48G+.
        
               | lucgommans wrote:
               | GRPN for anyone else who doesn't know it:
               | http://lashwhip.com/grpn.html
               | 
               | What I meant to say is that, if one uses a featureful
               | calculator like qalc, then you get unit conversion
               | included without needing two separate utilities. Of
               | course, if you've used a(n obscure) calculator for
               | decades then it may be easier to learn to use a separate
               | unit convertor instead
        
         | nayuki wrote:
         | I did the calculation manually from memory: 3.6 km/h = 1 m/s. 1
         | g = 9.8 m/s^2.
         | 
         | So, 100 km/h = 27.8 m/s. 36 m/s in 0.956 s is an average
         | acceleration of 29.1 m/s^2. Divide that by 9.8 m/s^2 to get
         | 2.96 g.
        
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       (page generated 2023-09-12 23:01 UTC)