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# Hit me at 30, and there's an 80% chance I'll live... watch

1. (Original post by spex)
No sarcasm meter has yet been invented that works on the internet :/ Some say it's theoretically impossible to build.
Oh can you post a link to one which works in real life then?
2. I was thinking it was about age. I laffed
3. (Original post by tommm)
Why don't you, y'know, just not hit a child in the first place?
4. It's accurate. We did the maths behind the impulse/momentum of a vehicle in physics a couple of years ago and the actual force applied to a pedestrian increases dramatically with an extra 10mph.
5. (Original post by mahaneap)
...Hit me at 40 and there's an 80% chance I'll die.

I'm sure you've all seen this advert. Here it is -

Is this true? I, for one, would like to see a source on this shocking statistic. Have the DVLA been out hitting children with cars at varying speeds? If so, this is terrible.

If not, they are making unsubstantiated claims of research which they have never done, which in my opinion, is far worse.
How could you think making up statistics is worse than hitting children with cars lol
6. They might drive cars into people that are already dead and assess the damage and the likelyhood of death from injurys sustained...

plus everything else other people mentioned.... but still. Cadavers rock.
7. (Original post by pokergod)
How could you think making up statistics is worse than hitting children with cars lol
Don't worry. Assuming equal numbers of children were "tested", 50% of the children used in the study survived.

Of course, that's only if they didn't decide to reuse the ones that survived, although I think that's unlikely due to any pre-existing injuries making a subsequent death more likely.

(Original post by Chiko 1001)
It's accurate. We did the maths behind the impulse/momentum of a vehicle in physics a couple of years ago and the actual force applied to a pedestrian increases dramatically with an extra 10mph.
True. This is due to kinetic energy being proportional to the square of velocity I believe. This kind of maths / physics can tell you the forces acting on a body, but only practical tests can show how these forces affect said body.
8. (Original post by GazzyG)

I'll hit you at 30.

Let's see you live.

The machines industry's name is called 'krupp' too...which sounds quite ominous.

9. If there are children about then drive slower since one of them could be a retard and run out in front of you. Then drive faster in a lower gear to make loads of noise so that they wouldn't dare to run out in front of you.
10. (Original post by mahaneap)
...Hit me at 40 and there's an 80% chance I'll die.

I'm sure you've all seen this advert. Here it is -

Is this true? I, for one, would like to see a source on this shocking statistic. Have the DVLA been out hitting children with cars at varying speeds? If so, this is terrible.

If not, they are making unsubstantiated claims of research which they have never done, which in my opinion, is far worse.
Let's do A level physics...

momentum = mass x velocity
force= 1/2 x mass x velocity x velocity

1150kg renault clio.

force @ 30mph = 495000 kg.mph^2
force @ 40mph = 880000 kg.mph^2

So, hitting at 40mph instead of 30mph gives a 78% increase in the force said kid gets hit with. That stat suddenly doesn't seem so far fetched huh?
11. (Original post by mahaneap)
Have the DVLA been out hitting children with cars at varying speeds? If so, this is terrible.

If not, they are making unsubstantiated claims of research which they have never done, which in my opinion, is far worse.
oh the mental image of them doing this
12. (Original post by xinjaing)
If there are children about then drive slower since one of them could be a retard and run out in front of you. Then drive faster in a lower gear to make loads of noise so that they wouldn't dare to run out in front of you.
You raise an interesting point. If children weren't taught about how to stay safe near roads, and drivers were instructed to run down any children they encounter on the roads, selection would soon produce a race of humans which were absolutely petrified of cars

(Original post by El Stevo)
Let's do A level physics...

momentum = mass x velocity
force= 1/2 x mass x velocity x velocity

1150kg renault clio.

force @ 30mph = 495000 kg.mph^2
force @ 40mph = 880000 kg.mph^2

So, hitting at 40mph instead of 30mph gives a 78% increase in the force said kid gets hit with. That stat suddenly doesn't seem so far fetched huh?
I don't doubt the statistic. I doubt the methods used to obtain it. A 78% increase in force is easy enough to calculate, but how does this correspond to the percentage likelihood of death?
13. (Original post by El Stevo)
Let's do A level physics...

momentum = mass x velocity
force= 1/2 x mass x velocity x velocity

1150kg renault clio.

force @ 30mph = 495000 kg.mph^2
force @ 40mph = 880000 kg.mph^2

So, hitting at 40mph instead of 30mph gives a 78% increase in the force said kid gets hit with. That stat suddenly doesn't seem so far fetched huh?
What grade did you get in your a level physics because force does not = .5mv^2 . Rookie mistake.

What you want is the coefficient of restitution, some velocity before and after measurements, and the conservation of momentum law. Then you can work out the energy change or force as needed.
14. (Original post by spex)
What grade did you get in your a level physics because force does not = .5mv^2 . Rookie mistake.

What you want is the coefficient of restitution, some velocity before and after measurements, and the conservation of momentum law. Then you can work out the energy change or force as needed.
oop. i meant kinetic energy. i only wrote force because i was thinking 'how hard he got hit'. schoolboy error.
15. (Original post by radiated yoghurt)
I don't think the exact figures matter tbh. If you drive faster and hit someone there is more chance they will die. The point of this advert is to get you to slow down, not statistical accuracy
16. Probably used crash test dummies. There are organisations which test out safety matters like this, eg http://www.euroncap.com/home.aspx .
17. (Original post by GazzyG)

I'll hit you at 30.

Let's see you live.
WTF IS THAT?!
18. if you drive at 40, your probably going to brake and hit them at 30, so it fine. just dont go 50
19. (Original post by El Stevo)
Let's do A level physics...

momentum = mass x velocity
force= 1/2 x mass x velocity x velocity

1150kg renault clio.

force @ 30mph = 495000 kg.mph^2
force @ 40mph = 880000 kg.mph^2

So, hitting at 40mph instead of 30mph gives a 78% increase in the force said kid gets hit with. That stat suddenly doesn't seem so far fetched huh?
i agree 100%with ur maths, but when a sober driver sees a kid he wd start applyin the brakes, so losing part of the K.E. as well there is plastic bumper that would hit the kid first and would break takin part of the K.E, when it breaks the surface area incontact with the kids body increases, and the force would be applied on a larger surface.
in addition to that there is probably a 1000 thing to take into account, even the position of the kid just before impact.
20. What if you're at 35?

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