Will the fastest man in the world ever run 100m in 1 second?

Wibbs

seamus wrote: »

Actually I don't think so.

In order to actually clear the 100m in one second from a standing start, you need to accelerate above 100m per second. That's because after 0.5 seconds you will only be doing 50m/s and will only have covered about 20m. So if we assume that the person is actually doing 200m/s when they cross the finish line, then the acceleration they experience for that 1 second is 20g.

Which is relatively small in terms of catastrophic forces. Forces in a car crash are often 2 or 3 times that and people walk away from it. So 20g is certainly tolerable for 1 second and almost certainly survivable without any permanent injury - that is, if you're strapped into a rocket.

Aye but the g forces on your legs to drive you forward are the problem. To take your car analogy, accelerating slowly up to 20 mph you'd barely notice, but the pistons in the engine are pulling serious g forces to do it. As it is Bolt generates something like a metric tonne of force in his legs every time his foot hits and pushes off. Maybe our bones and joints could take more, but our muscles would have to contract faster and with more power too.

Our bipedal motion fecks with us too. If you look at a cheetah it can keep it's feet on the ground for longer generating much more force while still driving forward. We kinda skip across the surface by comparison. Plus they got 4 wheel drive* Other bipeds of sorts like kangaroos get around this by hopping(among other things) so they don't have the issue of how fast they can put one leg in front of the other.



*funny enough where we can beat many a fast animal is downhill. Two legs are better there. Four legs tends to screwup and tumble. American Indians used to catch rabbits that way. Corral them so they had to run downhill and they'd catch them easily enough. The other way they and others caught swifter prey was through endurance. They'd run them down and knacker them out. Few enough animals have the endurance of fit humans. Something like a cat is faster than a human, but Tibbles would be fooked over ten K. Hell lions and tigers even cheetahs would be buggered. Dogs have us there mind you. Faster over short distances and can keep on going like duracell bunnies. Wolves and sled dogs can do 100+K a day without breaking much of a sweat.

SpiderHead

ok, what about if you strap the runner to a aircraft flying at about 340 mps, that stops suddenly shooting the runner forward and using those blade type prosthentic legs they only need to take 1 or 2 steps in that 100 meter span ?

Plane

---

/Stop/Runner

---

step

---

finish/ boom no problem !

bnt

Objects don't move at multiples of their terminal velocity (v_term) - if they did, it wouldn't be a "terminal velocity", would it? But it seems some folks here are assuming there is one v_term, and there isn't.

There isn't even a single v_term for a skydiver. The standard figure is for a typical skydiver falling in the standard face-down position, around 195 km/h. The same skydiver can tilt forward and nosedive, presenting a smaller area to the wind, and so his/her terminal velocity is higher. It also depends on your mass, so a heavier person will fall faster than a lighter person, assuming the frontal area is the same. If it's not, then the figures change again.

That formula Tiddlypeeps quoted has to take all that in to account, using the area and the drag coefficient. Car makers quote drag coefficients all the time in their ads, because (all else being equal) it has an impact on fuel economy. A few years ago I used the formula to calculate (roughly) that you could drop a Mini from a plane and its terminal velocity would be greater than the speed of sound - but only if you could keep it perfectly nose-down. It still wouldn't break the speed of sound, though - it's called the "sound barrier" for a reason ...

furiousox

Cats always land on their feet.
Toast always lands buttered side down.
Tape buttered toast to cat.
Throw cat off building.
Cat will hover.
Fact.

sbsquarepants

bnt wrote: »

A few years ago I used the formula to calculate (roughly) that you could drop a Mini from a plane and its terminal velocity would be greater than the speed of sound - but only if you could keep it perfectly nose-down. It still wouldn't break the speed of sound, though - it's called the "sound barrier" for a reason ...

Why would it not break the speed of sound? Felix Baumgartner did!

Tiddlypeeps wrote: »

Hmm, you are right, for some reason the terminology only refers to something falling under gravity but I can't see why.

The principal should be the same:

Th terminal velocity an object is equal to sqrt(2mg/pAC)

Where mg is weight, p is density of the fluid, A is area and C is the drag coefficient.

Gravity is just acceleration and doesn't factor into the formula (except for calculating weight, but that's the same weither falling or running), it shouldn't matter how long it takes you to reach that speed the effects of the fluid the object is passing through should be the same regardless. Am I missing something?



This doesn't make sense to me. Can you show me an example or explain how it works?

Sorry, i thought terminal velocity only applied to acceleration under gravity, and consequently anything that was accelerated past 9.8m/s/s to be exceeding that. If it applies to any acceleration, then obviously it can't be exceeded.

mewithoutyou

I dont think its possible personally. Who knows though, were getting pretty good as humans these days

donegal_road

skydivers occasionally get to a rate of 100m per second, you have to be falling for over 400m before you reach 60m per second

3qsmavrod5twfe

This is one serious hypothetical situation.

Capt'n Midnight

KyussBishop wrote: »

If someone could run that fast, all that would be left of them if they tripped up, would be a long red splat mark on the ground.

doesn't T Rex have the same problem , but more due to weight ?

ScumLord

This came up in a focus article recently (during the olympics). Modern athletes are at the edge of what's possible and it has little to do with power but reaction times of muscles and the time they have to lay down power. Most runners have loads of power left it's just their feet aren't on the ground long enough to put all the power down. When they lift their leg to take the next stride is also a bottleneck.

I'm just trying to recall stuff here and I may be getting it wrong but the reasons we can't run faster aren't due to power it's just down to the mechanics of our legs in between strides that causes problems. There is a muscle reaction time that can't be passed through any amount of training, that being the amount of time in milliseconds that it takes for the signal to go from the brain to the leg.

They went into body types as well. These days you need to have the right type of body to compete.

Bar introducing drugs we're only going to see very minor advancements in lap times.

Capt'n Midnight

seamus wrote: »

So if we assume that the person is actually doing 200m/s when they cross the finish line, then the acceleration they experience for that 1 second is 20g

Kinetic energy is 0.5 m v^2
and since it's over one second this gives the wattage they'd need to expend

so if the person weighed 75Kg they'd need to pump out 1.5 Megawatts just to cover the acceleration. Wind and ground resistance are extra. Breathing and beating are extra.

And since muscles are about 25% efficient you are going to be producing as much heat as a couple of thousand two bar heaters.

Monty - the one and only

Allyall wrote: »

Assuming that records are just going to keep getting broken, Will the fastest man in the world be 9 foot tall at some stage, and will it ever be ran in 1 second?

only if hes fired out of a rail gun... or some such.... but run it, no

ScumLord

http://sciencefocus.com/feature/physics/could-anyone-go-faster-usain-bolt

That's a short version of the article.

allibastor

SV wrote: »

To be running at 100metres a second you'd have to be doing over 230mph or 360kmh.
That's not counting the acceleration either.

I don't think the world will survive long enough to see evolution of that kind.



The end result is still them teleporting.
They'd have to run from the start to the end point for it to be valid.

And anyway, Humans wont evolve to run that fast unless our prey can move that fast also. The way things are going with us it would want to be a fast mcdonalds to do that.

rossie1977

the fastest land animal on earth is the cheetah, the fastest a cheetah has run 100 metres in controlled conditions was 5.95 seconds in 2012, thats the first time the 6 seconds barrier for a cheetah was broken and measurements of this kind have been taking place for years

ScumLord

allibastor wrote: »

And anyway, Humans wont evolve to run that fast unless our prey can move that fast also. The way things are going with us it would want to be a fast mcdonalds to do that.

What I love about humans is we often come up with novel or plan crazy alternatives that mean we don't have to evolve. One day a human decided not to run from the lion and instead stand his ground, he completely conflustered the lion to the point it didn't know how to react when things didn't run away from it. Next thing you know humans are just walking up to the lions kill taking it's food and walking away again, like a boss.

Three Seasons

The OP should study limits of sequences and series.

Capt'n Midnight

rossie1977 wrote: »

the fastest land animal on earth is the cheetah, the fastest a cheetah has run 100 metres in controlled conditions was 5.95 seconds in 2012, thats the first time the 6 seconds barrier for a cheetah was broken and measurements of this kind have been taking place for years

OMG they're evolving :eek:

Wibbs

ScumLord wrote: »

What I love about humans is we often come up with novel or plan crazy alternatives that mean we don't have to evolve.

+1000 SL. Recalling a previous thread along the lines of "what's so special about us we're just another animal", you've just summed it up perfectly IMH. We're a shíte carnivore? No worries Ted, Aisling has just invented this fire thing and wait'll you see what Brian's been doing with pointy sticks and rocks. Can't run too fast? Let's piggy back on a horse or camel, or for the truly mad bastards an elephant. How utterly huge were the balls on the first Indian bloke who looked at an elephant and thought "y'know I reckon I could use that lad for transport". He needed an elephant just to bear the weight of his liathroidi. "Jaysus I envy birds I do". "Fcuk birds Jim, I've just invented Concorde". Usain Bolt, an amazing human being with incredible drive and perseverance and still a granny with a heavy right foot in her Yaris can blast right by him.

Watching the Olympics and such is almost like a nostalgic cultural and community event where we watch fellow humans do things without all the cool non evolutionary stuff we've cooked up since.

cabledude

suicide_circus wrote: »

I can do the 100 in 1 second.



Falling.

No you can't. Not on Earth at least. On Earth you'd cover around 9.8 m in that second. Roughly.

Capt'n Midnight

Wibbs wrote: »

We're a shíte carnivore? No worries Ted,

We are the best persistence hunter during the hottest part of the day, we keep our cool because we are the naked ape.

Run a few miles, jog 20, swim a river, climb a tree and then throw rocks at you. There's only one organism for that job. And it's fairly omnivorous.

We're pretty badass. Not to shabby on our own, but we can organise packs of 150. And that's pack's not herds.

Baboons can protect their troop from leopards. Imagine a troop of baboons with smaller teeth. But bigger and there's more of them and they're persistent.

https://www.youtube.com/watch?v=826HMLoiE_o

desertcircus

The realistic lower limit is around the nine second mark. To go beyond that, you'd need to start looking at heat regulation in the human body, the speed at which muscle fibres can contract and relax, and the level of force a human bone can withstand before snapping.