REAL close one this evening.....

MatteH Oxford said:
Perhaps it would be like a 75mph crash, the 150mph speed shared between both vehicles? Or perhaps different vehicle mass has a factor?

Dunno, it would be interesting to find out as I'm sure that two vehicles of similar size share the impact force pretty much 50/50 if they both collide at the same speed. For instance, 50mph per car, 100mph combined speed, roughly 50/50 share of total impact force = impact is basically like a 50mph crash into solid object.

Maybe? :confused::D
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No, it's not like crashing into a solid object at 50mph, as you've got two cars wrecked not one, so twice the energy of a 50mph crash, but shared between the two. I can see why it might appear to be like one car crashing into a solid object, but it's not the right way to look at it, as there are two cars involved.
 
hughtrimble said:
No, it's not like crashing into a solid object at 50mph, as you've got two cars wrecked not one, so twice the energy of a 50mph crash, but shared between the two. I can see why it might appear to be like one car crashing into a solid object, but it's not the right way to look at it, as there are two cars involved.
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The damage to each vehicle would be similar to crash into a stationary object though right?
 
I don't need to know impact speeds, I just know if an S Type Jag hits a stationery MX5 which it would have been come impact at around 100mph it is going to hurt.
 
mjt said:
Are people going to say this after every incident on the road now? :rolleyes:
I highly doubt a dashcam would've been able to read the number plate of a fast-approaching S-Type with its headlights (and main beams!) on at night.

Glad to hear you and your wife are OK Housey!
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I didn't mean in the sense of using it to prosecute the driver but more so we could have seen it.
 
I doubt you'd have felt a thing !!

The Jag would probably have ridden up and over your MX5 and taken both your heads with it !

And that's the problem with Vehicular Incidents

Oopsie .. I didn't mean it.

Slapped wrists for him but you and your loved ones are gone forever !
 
Housey said:
It was daylight but frankly not sure what a dash cam could have added other than a scary video of what could have happened. It was VERY close to a head on of probably 150mph combined speed as my wife was doing circa 50mph at the time. S type Jag v MX5 is not going to end well for the Mazda I fear.
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Freefaller said:
No - if 2 cars hit each other at 50mph it will just be as if the car hit a wall at 50mph.
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Not so, because the two-50-mph-car crash releases far more energy than a car at 50 mph crashing into a (immovable) wall.

2 identical cars each going 50 mph colliding into each other release the same energy as one of the cars going about 70 mph into a wall. (Assuming a perfectly inelastic collision - in reality the cars will deform and pieces will come off, releasing substantial amounts of this energy.)

Edit: Error on my part. This is true considering all the kinetic energy (from both cars) but obvs that energy is distributed over both cars in a two-car collision. If half the energy goes into each car then it's the same as the car smashing into a wall.

Links:
Equations from https://en.wikipedia.org/wiki/Inelastic_collision
http://physics.stackexchange.com/qu...-same-as-one-car-colliding-into-a-wall-at-100
 
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Glad it was nothing more serious.

I'm finding every day driving standards are really changing. I cycle 4-800 miles a month if I can be bothered, I drive and ride horses. From all aspects it's just getting silly.

There's either overly cautious or just insane stupidity. Not only are people just seemingly distracted with themselves, there are people who just stick it all on red and take huge risks only to be caught up to at the next obstacle.

I have near misses on all forms of transport every other day some honest mistakes, others ignorance. The roads have become an unpleasant place to be and no fun at all even at quiet times of the day. It's no wonder there's so many militant road rage videos these days with the stress levels flying high. All I want do is make steady progress and get to where I'm going safely and on time. Seems like a lot to ask these days.
 
joeyjojo said:
Not so, because the two-50-mph-car crash releases far more energy than a car at 50 mph crashing into a (immovable) wall.

2 identical cars each going 50 mph colliding into each other release the same energy as one of the cars going about 70 mph into a wall. (Assuming a perfectly inelastic collision - in reality the cars will deform and pieces will come off, releasing substantial amounts of this energy.)

In the example of an 1800 kg S type at 100 mph vs a 1000 kg mx5 at 50 mph I guestimate it'd be roughly like smashing the mx5 into a wall at 128 mph. In other words, very lucky escape Housey!!

(Equations from https://en.wikipedia.org/wiki/Inelastic_collision)

Read more examples: http://physics.stackexchange.com/qu...-same-as-one-car-colliding-into-a-wall-at-100
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I was talking about the scenario described about 2 cars hitting one another at 50mph - not the example that Housey was in.

I know that in Housey's situation they'd accelerate quickly backwards at around 60mph in this situation.

I realise that the colliding force of 2 cars hitting each other at 50mph is greater than hitting a wall, but 2 cars are able to absorb the impact (i.e. the force is spread over 2 cars), that's all I was suggesting - so the damage to 2 cars hitting each other at 50mph, would be the same as a car running into a wall at 50mph, and not 100mph - again this is not Housey's scenario, just the 2 cars hitting one another at 50mph - of course this assumes the cars are roughly the same mass. In Housey's situation it would have been significantly different owing the mass difference of the cars.
 
joeyjojo said:
Not so, because the two-50-mph-car crash releases far more energy than a car at 50 mph crashing into a (immovable) wall.
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Not read your links but the kinetic energy of 2 identical cars just before they head on at 50 mph is twice the energy of 1 car crashing into a stationary wall. BUT the energy is spread over 2 vehicles so each car feels a head on at 50 mph as the same as crashing into a stationary wall at 50 mph.
 
Fishman said:
Not read your links but the kinetic energy of 2 identical cars just before they head on at 50 mph is twice the energy of 1 car crashing into a stationary wall. BUT the energy is spread over 2 vehicles so each car feels a head on at 50 mph as the same as crashing into a stationary wall at 50 mph.
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Not quite. Energy dispersion is what's important. One car could take more energy than the other.
 
The dash cam would have added a video for everyone else to watch, I don't see it would have added much more. I would not expect the police would have taken it and used it for a prosecution for example. I am also not the sort of person who seeks to embarrass someone on the internet, we all make mistakes, it's just annoying and frankly scary to be at the end of one at this speed. It was a bad bit of driving, very bad with the speed and risk taken but there for the grace of God etc.

Just write it down to lucky and move on.
 
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