I am curious about the idea of flooring the throttle of a vehicle to avoid a collision. It’s very common, especially among blokes.

I think if we looked at the physics of it, we would find that in almost every single case, all the acceleration has achieved is to add energy to the crash.

I’m bringing this to the group because, as both excellent drivers and people who know things about physics, we are ideally positioned to unpack this urban myth.

Rule 303 said:

I am curious about the idea of flooring the throttle of a vehicle to avoid a collision. It’s very common, especially among blokes.

I think if we looked at the physics of it, we would find that in almost every single case, all the acceleration has achieved is to add energy to the crash.

I’m bringing this to the group because, as both excellent drivers and people who know things about physics, we are ideally positioned to unpack this urban myth.

There is going to be a lot of conditions on that one. The first is…how far away from the imminent collision are you? Is there actually enough space to get out of the way?

Rule 303 said:

I am curious about the idea of flooring the throttle of a vehicle to avoid a collision. It’s very common, especially among blokes.

I think if we looked at the physics of it, we would find that in almost every single case, all the acceleration has achieved is to add energy to the crash.

I’m bringing this to the group because, as both excellent drivers and people who know things about physics, we are ideally positioned to unpack this urban myth.

My dad was involved in speed versus reaction times tests iincluding those involved with alcohol consumption. Cannot relaibly give you a time and date but I’d suggest that it was between the wars.

There does exist a place in space and time continuum wherby an increase in acceleration will get you out. There was a time though when dad didn’t bother to accelerate because he thought he had right of way, which at the time was still true. A taxi driver knocked the tail light outer off without damaging the car. When the taxi driver tried to say it was dad’s fault he replied, “I’ve driven three million mjiles and you have just caused my first involvement in a vehicle collision”.

Rule 303 said:

I am curious about the idea of flooring the throttle of a vehicle to avoid a collision. It’s very common, especially among blokes.

I think if we looked at the physics of it, we would find that in almost every single case, all the acceleration has achieved is to add energy to the crash.

I’m bringing this to the group because, as both excellent drivers and people who know things about physics, we are ideally positioned to unpack this urban myth.

There would be circumstances in which you can sensibly choose to accelerate to avoid a collision. I have no opinion on whether the average driver is equipped to make that choice.

dv said:

Rule 303 said:

I am curious about the idea of flooring the throttle of a vehicle to avoid a collision. It’s very common, especially among blokes.

I think if we looked at the physics of it, we would find that in almost every single case, all the acceleration has achieved is to add energy to the crash.

I’m bringing this to the group because, as both excellent drivers and people who know things about physics, we are ideally positioned to unpack this urban myth.

There would be circumstances in which you can sensibly choose to accelerate to avoid a collision. I have no opinion on whether the average driver is equipped to make that choice.

Indeed this skill may be instinct but in many it requires a lot of practice.

Rule 303 said:

I am curious about the idea of flooring the throttle of a vehicle to avoid a collision. It’s very common, especially among blokes.

I think if we looked at the physics of it, we would find that in almost every single case, all the acceleration has achieved is to add energy to the crash.

I’m bringing this to the group because, as both excellent drivers and people who know things about physics, we are ideally positioned to unpack this urban myth.

It depends on the situation and the driver/s.
I had a right rear suspension strut collapse on my car as it was negotiating a tight left hander.
The car immediately attempted to run wide into oncoming traffic. Braking would have meant a collision was inevitable. The car was front wheel drive so added throttle meant the car dragged itself off the inside of the corner and thus away from the right hand side of the road.

buffy said:

Rule 303 said:

I am curious about the idea of flooring the throttle of a vehicle to avoid a collision. It’s very common, especially among blokes.

I think if we looked at the physics of it, we would find that in almost every single case, all the acceleration has achieved is to add energy to the crash.

I’m bringing this to the group because, as both excellent drivers and people who know things about physics, we are ideally positioned to unpack this urban myth.

There is going to be a lot of conditions on that one. The first is…how far away from the imminent collision are you? Is there actually enough space to get out of the way?

I’m suggesting that applying the maximum acceleration the vehicle is capable of is very unlikely to make enough difference to the position of the vehicle to actually get it ‘out of trouble’.

I floored it when I misjudged the speed of a an approaching car at an intersection or saw it late. Braking hard would not have worked.

probably helpful in some situations, not usually though

the idea to some extent probably comes from the opposite, which is to lose steering control and more under braking, or even of deceleration some possibilities are lost

of another example, motorbikes, say dirtbike, which is possibly instructive, you absolutely use power to dig the back wheel in and maintain control, or you have the power there to turn the back wheel with the power, slide it, keep it digging, and turn the power in whatever direction, away from obstacles, away from impacts if you get it right

there are certain obvious situations of powering out of a crash in a car, like you’re traveling down a dirt road with a trailer behind, the trailer gets the wobbles and is swinging one side of the road to the other wildly, i’ve seen it done changing back and gear and powering out of that situation, trailer straightened up quick

roughbarked said:

dv said:

Rule 303 said:

I am curious about the idea of flooring the throttle of a vehicle to avoid a collision. It’s very common, especially among blokes.

I think if we looked at the physics of it, we would find that in almost every single case, all the acceleration has achieved is to add energy to the crash.

I’m bringing this to the group because, as both excellent drivers and people who know things about physics, we are ideally positioned to unpack this urban myth.

There would be circumstances in which you can sensibly choose to accelerate to avoid a collision. I have no opinion on whether the average driver is equipped to make that choice.

Indeed this skill may be instinct but in many it requires a lot of practice.

That’s why we took our boys to car club with us and they did motorkhana stuff from a young age.

Rule 303 said:

buffy said:

Rule 303 said:

I am curious about the idea of flooring the throttle of a vehicle to avoid a collision. It’s very common, especially among blokes.

I think if we looked at the physics of it, we would find that in almost every single case, all the acceleration has achieved is to add energy to the crash.

I’m bringing this to the group because, as both excellent drivers and people who know things about physics, we are ideally positioned to unpack this urban myth.

There is going to be a lot of conditions on that one. The first is…how far away from the imminent collision are you? Is there actually enough space to get out of the way?

I’m suggesting that applying the maximum acceleration the vehicle is capable of is very unlikely to make enough difference to the position of the vehicle to actually get it ‘out of trouble’.

But it could mean corner to corner rather than head on.

dv said:

Rule 303 said:

I am curious about the idea of flooring the throttle of a vehicle to avoid a collision. It’s very common, especially among blokes.

I think if we looked at the physics of it, we would find that in almost every single case, all the acceleration has achieved is to add energy to the crash.

I’m bringing this to the group because, as both excellent drivers and people who know things about physics, we are ideally positioned to unpack this urban myth.

There would be circumstances in which you can sensibly choose to accelerate to avoid a collision. I have no opinion on whether the average driver is equipped to make that choice.

I’m thinking: A vehicle moving at 17m/s applies maximal acceleration, which at this speed is 1.1m/s, the effect of which is to move the collision 33mm down the road. The speed increase has added 550N to the crash.








(Numbers may have been plucked from the air)

I wish you’d named this floored physics.

I’ve only ever had one occasion to floor it to avoid an accident.
Side street coming into the street I was driving in, the car was stopped at the side street stop sign.
They obviously hadn’t seen me and started off, I gunned it and they just missed my arse end, it was a no brainer really.

Ian said:

I floored it when I misjudged the speed of a an approaching car at an intersection or saw it late. Braking hard would not have worked.

I did this in a (small) roundabout in Hamilton recently. I didn’t realize the car opposite me was planning on turning (no indicator) and he came into the roundabout at the same time as me – but faster…

Ian said:

I floored it when I misjudged the speed of a an approaching car at an intersection or saw it late. Braking hard would not have worked.

This is the classic scenario. See a hazard at the last minute and floor the throttle in what I can only assume is a ‘flight’ reaction.

What I’m asking is, does the physics actually support that strategy? Or should we be braking? Or spending our time looking at where the car will go if we do get hit?

Ian said:

I floored it when I misjudged the speed of a an approaching car at an intersection or saw it late. Braking hard would not have worked.

I’ve done that as well on the road, and once on the racing track when braking into a corner – The car behind me had started to spin so I got off the brakes and steered & accelerated out of the way.
But agreed, there’s not a lot of times where giving the car a boot full will make things better for you.

Arts said:

I wish you’d named this floored physics.

Thought about it, decided this was better. Don’t want to be causing anneurysms in our pedants. Thanks for noticing.

Peak Warming Man said:

I’ve only ever had one occasion to floor it to avoid an accident.
Side street coming into the street I was driving in, the car was stopped at the side street stop sign.
They obviously hadn’t seen me and started off, I gunned it and they just missed my arse end, it was a no brainer really.

>nods<

This urban myth has legs, aye?

Rule 303 said:

Peak Warming Man said:

I’ve only ever had one occasion to floor it to avoid an accident.
Side street coming into the street I was driving in, the car was stopped at the side street stop sign.
They obviously hadn’t seen me and started off, I gunned it and they just missed my arse end, it was a no brainer really.

>nods<

This urban myth has legs, aye?

you really need data from people who have tried this and the outcome was not positive…

Seems like it’s probably a matter of awareness of the other buggers on the road, really. I have on rather too many occasions had to brake from 100 to sometimes a stop when someone coming the other way has misjudged a semi or B double passing manoeuvre. But most of my driving is highway driving, so that is to be expected.

Arts said:

Rule 303 said:

Peak Warming Man said:

I’ve only ever had one occasion to floor it to avoid an accident.
Side street coming into the street I was driving in, the car was stopped at the side street stop sign.
They obviously hadn’t seen me and started off, I gunned it and they just missed my arse end, it was a no brainer really.

>nods<

This urban myth has legs, aye?

you really need data from people who have tried this and the outcome was not positive…

Thing is, if you have taken the time to think about it, then you are way too late.

some of the idea might come from the reality that the physics (familiarity) of vehicles under heavy braking is probably a weakness in many, perhaps most drivers, most drivers know the accelerator much better

but how many people know .5M x (V^2) = KE well at all, especially that exponentiation V^2, what it means for braking, clearly not the people driving the vehicles I see behind me at times

Here you go

Arts said:

Rule 303 said:

Peak Warming Man said:

I’ve only ever had one occasion to floor it to avoid an accident.
Side street coming into the street I was driving in, the car was stopped at the side street stop sign.
They obviously hadn’t seen me and started off, I gunned it and they just missed my arse end, it was a no brainer really.

>nods<

This urban myth has legs, aye?

you really need data from people who have tried this and the outcome was not positive…

The collected anecdotes would suggest this would include everyone who has ever been T-boned.

roughbarked said:

Arts said:

Rule 303 said:

>nods<

This urban myth has legs, aye?

you really need data from people who have tried this and the outcome was not positive…

Thing is, if you have taken the time to think about it, then you are way too late.

huh?

Rule 303 said:

Arts said:

Rule 303 said:

>nods<

This urban myth has legs, aye?

you really need data from people who have tried this and the outcome was not positive…

The collected anecdotes would suggest this would include everyone who has ever been T-boned.

Mostly those T-boned, never looked until the lights hit them.

Rule 303 said:

Ian said:

I floored it when I misjudged the speed of a an approaching car at an intersection or saw it late. Braking hard would not have worked.

This is the classic scenario. See a hazard at the last minute and floor the throttle in what I can only assume is a ‘flight’ reaction.

What I’m asking is, does the physics actually support that strategy? Or should we be braking? Or spending our time looking at where the car will go if we do get hit?

This was a doozie of an intersection.. coming down a steep hill to a stop sign.. shrubbery and embankments to impede vision. Long time ago, I probably didn’t stop fully. Through the intersection the road went down an extremely steep hill.. I was nearly airborne. Anyway, was good result.

Rule 303 said:

Arts said:

Rule 303 said:

>nods<

This urban myth has legs, aye?

you really need data from people who have tried this and the outcome was not positive…

The collected anecdotes would suggest this would include everyone who has ever been T-boned.

You’d have to hope the person doing the T-boning wasn’t thinking flooring it would be helpful…

Arts said:

roughbarked said:

Arts said:

you really need data from people who have tried this and the outcome was not positive…

Thing is, if you have taken the time to think about it, then you are way too late.

huh?

Reaction times. There is little room for error.

Rule 303 said:

Arts said:

Rule 303 said:

>nods<

This urban myth has legs, aye?

you really need data from people who have tried this and the outcome was not positive…

The collected anecdotes would suggest this would include everyone who has ever been T-boned.

everyone who has been toned and tried to floor it milliseconds before… I suspect that there are a number of accidents where, on instant perception, braking hard would be a response… I wouldn’t exactly call that a ‘fight or flight’ response either that suggests that the people who hit the brake are ‘fighting’? .. wait, is there an Oh Fuck! response?

Ian said:

Rule 303 said:

Ian said:

I floored it when I misjudged the speed of a an approaching car at an intersection or saw it late. Braking hard would not have worked.

This is the classic scenario. See a hazard at the last minute and floor the throttle in what I can only assume is a ‘flight’ reaction.

What I’m asking is, does the physics actually support that strategy? Or should we be braking? Or spending our time looking at where the car will go if we do get hit?

This was a doozie of an intersection.. coming down a steep hill to a stop sign.. shrubbery and embankments to impede vision. Long time ago, I probably didn’t stop fully. Through the intersection the road went down an extremely steep hill.. I was nearly airborne. Anyway, was good result.

Templestowe? Foote Street? (Is it still like that? Far more builtup now than in the 1970s)

buffy said:

Rule 303 said:

Arts said:

you really need data from people who have tried this and the outcome was not positive…

The collected anecdotes would suggest this would include everyone who has ever been T-boned.

You’d have to hope the person doing the T-boning wasn’t thinking flooring it would be helpful…

right. I was also thinking that the flooring response was for those trying to avoid collision.

roughbarked said:

Arts said:

roughbarked said:

Thing is, if you have taken the time to think about it, then you are way too late.

huh?

Reaction times. There is little room for error.

sure, but if the reaction is to floor it… then we can’t create a result based on those who have said “I floored it and was safe”. we also need those who have floored it but it still resulted in a collision. Or those who floored it and BECAUSE of that it resulted in a collision..

we really have four items here… those who floor it and it results in no collision
those who floor it and it results in a collision
those who brake and it results in no collision
those who brake and it results in a collision.

and then I suppose, those who do nothing and it results in a. collision or no collision…

six.. six items..

roughbarked said:

Arts said:

roughbarked said:

Thing is, if you have taken the time to think about it, then you are way too late.

huh?

Reaction times. There is little room for error.

There is lots of evidence that when it comes to complex movements in high-speed sports, anticipation is many times more important than reaction time. I would suggest that when it comes to the time frames that vehicle collisions happen in, if there’s any reaction it would only change the post-collision movement of the vehicle.

buffy said:

Ian said:

Rule 303 said:

This is the classic scenario. See a hazard at the last minute and floor the throttle in what I can only assume is a ‘flight’ reaction.

What I’m asking is, does the physics actually support that strategy? Or should we be braking? Or spending our time looking at where the car will go if we do get hit?

This was a doozie of an intersection.. coming down a steep hill to a stop sign.. shrubbery and embankments to impede vision. Long time ago, I probably didn’t stop fully. Through the intersection the road went down an extremely steep hill.. I was nearly airborne. Anyway, was good result.

Templestowe? Foote Street? (Is it still like that? Far more builtup now than in the 1970s)

This was Gertrude St and Etna St, Gosford.. not far from home.

For some reason Google doesn’t recognise the well known aphorism “sometimes an ounce of accelerator is worth a ton of brakes” :)

also with Modern Electric Vehicles the response time of the vehicle itself is far more amenable to the use of accelerator to modify the velocity of a vehicle

Arts said:

Rule 303 said:

Arts said:

you really need data from people who have tried this and the outcome was not positive…

The collected anecdotes would suggest this would include everyone who has ever been T-boned.

everyone who has been toned and tried to floor it milliseconds before… I suspect that there are a number of accidents where, on instant perception, braking hard would be a response… I wouldn’t exactly call that a ‘fight or flight’ response either that suggests that the people who hit the brake are ‘fighting’? .. wait, is there an Oh Fuck! response?

Yeah, that’s what most people do. Freeze. No change to vehicle control inputs other than maybe stabbing a pedal. Which pedal to stab would seem to be the thrust of the discussion.

maybe we should ask some pilots whether there are many situations when adding power and or climbing would be appropriate to avert collision

for a discussion on thrust we would presume that the accelerator is the correct associated pedal

it’s probably a bit like nurses getting their gloves dirty, it’s almost always correct to use the brake in the same way that gloves should almost always remain clean

why wasn’t the thread entitled floored physics

SCIENCE said:

why wasn’t the thread entitled floored physics

From: Arts
ID: 1697474
Subject: re: Flawed Physics
I wish you’d named this floored physics.

Witty Rejoinder said:

SCIENCE said:

why wasn’t the thread entitled floored physics

From: Arts
ID: 1697474
Subject: re: Flawed Physics
I wish you’d named this floored physics.

how does it feel to know you’ve stooped to my level?

Witty Rejoinder said:

SCIENCE said:

why wasn’t the thread entitled floored physics

From: Arts
ID: 1697474
Subject: re: Flawed Physics
I wish you’d named this floored physics.

thanks but why

and since it’s not called twisted physics, what do you all think about steering the vehicle, accelerator or brake or no, to avert collision, or is that also considered just a recipe for increasing the risk

SCIENCE said:

also with Modern Electric Vehicles the response time of the vehicle itself is far more amenable to the use of accelerator to modify the velocity of a vehicle

Putting aside for a moment that I think that’s only likely to be true at very low speeds, which is where the difference in torque delivery is greatest, the question of whether a very high powered vehicle that accelerates very quickly has any advantage is worth thinking about.

First question – Is the vehicle’s ability to accelerate likely to be the determining factor?

We have probably all been in this situation: You’re approaching a roundabout and the A pillar conceals a car coming from your right. You enter the roundabout and see the car, at which point you’re committed and if you don’t get out of the way you’re going to get hit. It’s 10m away, traveling at 40km/hr.

You’re traveling at 35km/hr. An average car can accelerate at 1.1m/s in this situation, but you’re driving a supercar that can accelerate at 2m/s. You mash the pedal to the floor and the car launches.

Do you get hit? Is the difference in acceleration the determining factor?

conserving momentum, or not commonly features in decisions regard avoiding obstacles ahead (or from the side, or behind), involving motorized vehicles and otherwise, thing is if the situation looks potentially awkward involving a car, to maintain the throttle position as it was isn’t always likely given the attention jolt, you can in fact find yourself in a metastable state, some time is lost dithering between throttle and brake, anyone that has ever driven out onto a busy road would have experienced the dangers of that, the possibility of a crash caused by a moments procrastination, a lack of decisiveness

subject overtaking, this often involves accelerating to avoid obstacles, the whatever being overtaken, and oncoming traffic, in fact large part of overtaking is avoiding a crash

imagine a two lane road, one with oncoming traffic, there are in fact two ways of overtaking, one conserved momentum of the vehicle, the other doesn’t, of the latter generally the vehicle ahead is trailed, of the former sort momentum is conserved or gained from some distance back

people are always making decisions about whether to conserve momentum or not (or velocity if you like), largely done courtesy the native physics of the brain, geometry and more, intuitive geometry, kids can do it before they even go to school would you believe

transition said:

conserving momentum, or not commonly features in decisions regard avoiding obstacles ahead (or from the side, or behind), involving motorized vehicles and otherwise, thing is if the situation looks potentially awkward involving a car, to maintain the throttle position as it was isn’t always likely given the attention jolt, you can in fact find yourself in a metastable state, some time is lost dithering between throttle and brake, anyone that has ever driven out onto a busy road would have experienced the dangers of that, the possibility of a crash caused by a moments procrastination, a lack of decisiveness

subject overtaking, this often involves accelerating to avoid obstacles, the whatever being overtaken, and oncoming traffic, in fact large part of overtaking is avoiding a crash

imagine a two lane road, one with oncoming traffic, there are in fact two ways of overtaking, one conserved momentum of the vehicle, the other doesn’t, of the latter generally the vehicle ahead is trailed, of the former sort momentum is conserved or gained from some distance back

people are always making decisions about whether to conserve momentum or not (or velocity if you like), largely done courtesy the native physics of the brain, geometry and more, intuitive geometry, kids can do it before they even go to school would you believe

…..features in decisions regard avoiding obstacles ahead, _or becoming an obstacle__

Rule 303 said:

… but you’re driving a supercar that can accelerate at 2m/s.

More like 9 – 10 m/s^2.

Spiny Norman said:

Rule 303 said:

… but you’re driving a supercar that can accelerate at 2m/s.

More like 9 – 10 m/s^2.

Gee :)

I just close my eyes.

sibeen said:

Spiny Norman said:

Rule 303 said:

… but you’re driving a supercar that can accelerate at 2m/s.

More like 9 – 10 m/s^2.

Gee :)

I know it’s your absolute fave car, so you’ll be thrilled to know that the latest Tesla P100D Plaid+ can go 0 – 96 km/h in just under two seconds, a quarter mile in about 8.9 seconds and has over 1,000 hp.

JudgeMental said:

I just close my eyes.

Hehehehe.

actually one scenario we recall is trying to get away from some genius trying to merge into our rear corner, left or right, and it might be better than getting rammed full in the side

roundabout escape we’re not sure, would have to wait until we’re back somewhere with an envelope but can think about that one, we have seen other cars get away qwick however so maybe it does work

SCIENCE said:

actually one scenario we recall is trying to get away from some genius trying to merge into our rear corner, left or right, and it might be better than getting rammed full in the side

I experienced that today. person probably doesn’t know the difference certain lane markings make regarding right of way when merging.

I was driving through a residential area around 9pm last Saturday and after slowing at a roundabout, my significant other gasped and said GO GO GO ! I asked what she was on about when from the gloom appeared a cheery face of a man on an evening run coming towards the car – everything totally normal except he was naked and presumably trying to get into the car. I accelerated out trouble leaving him behind. Our child cried.

So yes, I would agree, accelerating can get you out of trouble.

wookiemeister said:

I was driving through a residential area around 9pm last Saturday and after slowing at a roundabout, my significant other gasped and said GO GO GO ! I asked what she was on about when from the gloom appeared a cheery face of a man on an evening run coming towards the car – everything totally normal except he was naked and presumably trying to get into the car. I accelerated out trouble leaving him behind. Our child cried.

So yes, I would agree, accelerating can get you out of trouble.

was that physics though

wookiemeister said:

I was driving through a residential area around 9pm last Saturday and after slowing at a roundabout, my significant other gasped and said GO GO GO ! I asked what she was on about when from the gloom appeared a cheery face of a man on an evening run coming towards the car – everything totally normal except he was naked and presumably trying to get into the car. I accelerated out trouble leaving him behind. Our child cried.

So yes, I would agree, accelerating can get you out of trouble.

He could have been some guy from the future, urgently trying to warn you about something dangerous to you.

SCIENCE said:

wookiemeister said:

I was driving through a residential area around 9pm last Saturday and after slowing at a roundabout, my significant other gasped and said GO GO GO ! I asked what she was on about when from the gloom appeared a cheery face of a man on an evening run coming towards the car – everything totally normal except he was naked and presumably trying to get into the car. I accelerated out trouble leaving him behind. Our child cried.

So yes, I would agree, accelerating can get you out of trouble.

was that physics though

Accelerating DID avoid a collision.

Spiny Norman said:

Rule 303 said:

… but you’re driving a supercar that can accelerate at 2m/s.

More like 9 – 10 m/s^2.

That’s quite fast, for a roundabout.

;-)

Rule 303 said:

wookiemeister said:

I was driving through a residential area around 9pm last Saturday and after slowing at a roundabout, my significant other gasped and said GO GO GO ! I asked what she was on about when from the gloom appeared a cheery face of a man on an evening run coming towards the car – everything totally normal except he was naked and presumably trying to get into the car. I accelerated out trouble leaving him behind. Our child cried.

So yes, I would agree, accelerating can get you out of trouble.

He could have been some guy from the future, urgently trying to warn you about something dangerous to you.

Maybe he wanted my clothes

wookiemeister said:

Rule 303 said:

wookiemeister said:

I was driving through a residential area around 9pm last Saturday and after slowing at a roundabout, my significant other gasped and said GO GO GO ! I asked what she was on about when from the gloom appeared a cheery face of a man on an evening run coming towards the car – everything totally normal except he was naked and presumably trying to get into the car. I accelerated out trouble leaving him behind. Our child cried.

So yes, I would agree, accelerating can get you out of trouble.

He could have been some guy from the future, urgently trying to warn you about something dangerous to you.

Maybe he wanted my clothes

Let’s not go crazy here.

Rule 303 said:

wookiemeister said:

Rule 303 said:

He could have been some guy from the future, urgently trying to warn you about something dangerous to you.

Maybe he wanted my clothes

Let’s not go crazy here.

We need your clothes, your boots, and your motorcycle.

Rule 303 said:

wookiemeister said:

Rule 303 said:

He could have been some guy from the future, urgently trying to warn you about something dangerous to you.

Maybe he wanted my clothes

Let’s not go crazy here.

Hang on I think there was another naked guy running robot style nearby but he was killed by a speeding Toyota landcruiser.

Rule 303 said:

I am curious about the idea of flooring the throttle of a vehicle to avoid a collision. It’s very common, especially among blokes.

I think if we looked at the physics of it, we would find that in almost every single case, all the acceleration has achieved is to add energy to the crash.

I’m bringing this to the group because, as both excellent drivers and people who know things about physics, we are ideally positioned to unpack this urban myth.

Never in my whole life have I floored the throttle to avoid a collision.
And I’ve never known anyone, bloke or otherwise, to do it.

Come to think of it, I was able to tell a bloke at men’s group some seven years ago that I’ve never floored the throttle in any car, ever. I did once, shortly after that, just to see, and never since.

I have been in one collision where it would have helped, when a vehicle backed into the side of the vehicle I was in. Flooring the throttle would have taken me out of the path of the oncoming backing vehicle.

Another situation would be when overtaking, when on the wrong side of the road. Flooring the throttle would greatly reduce the time to overtake the car on the left, should something suddenly appear straight ahead. At the same instant, the car being overtaken should brake.

Rule 303 said:

dv said:

Rule 303 said:

I am curious about the idea of flooring the throttle of a vehicle to avoid a collision. It’s very common, especially among blokes.

I think if we looked at the physics of it, we would find that in almost every single case, all the acceleration has achieved is to add energy to the crash.

I’m bringing this to the group because, as both excellent drivers and people who know things about physics, we are ideally positioned to unpack this urban myth.

There would be circumstances in which you can sensibly choose to accelerate to avoid a collision. I have no opinion on whether the average driver is equipped to make that choice.

I’m thinking: A vehicle moving at 17m/s applies maximal acceleration, which at this speed is 1.1m/s, the effect of which is to move the collision 33mm down the road. The speed increase has added 550N to the crash.








(Numbers may have been plucked from the air)

Those numbers seem a couple of orders of magnitude out.
An ordonary car can accelerate around 2.2 m/s/s at that speed. In a couple of seconds that will make a 4.4 metre difference, about a car length.

Kangaroos will leap from the bushes and try to run into a moving vehicle, slowing will only allow them to crash into you at speed and your slowing but still moving vehicle – I’ll normally accelerate to leave them behind me , still charging after me.

dv said:

Rule 303 said:

dv said:

There would be circumstances in which you can sensibly choose to accelerate to avoid a collision. I have no opinion on whether the average driver is equipped to make that choice.

I’m thinking: A vehicle moving at 17m/s applies maximal acceleration, which at this speed is 1.1m/s, the effect of which is to move the collision 33mm down the road. The speed increase has added 550N to the crash.








(Numbers may have been plucked from the air)

Those numbers seem a couple of orders of magnitude out.
An ordonary car can accelerate around 2.2 m/s/s at that speed. In a couple of seconds that will make a 4.4 metre difference, about a car length.

Hold on, if you have m/s/s can’t you just cancel out the s and get m.

confused from Essendon

sibeen said:

dv said:

Rule 303 said:

I’m thinking: A vehicle moving at 17m/s applies maximal acceleration, which at this speed is 1.1m/s, the effect of which is to move the collision 33mm down the road. The speed increase has added 550N to the crash.








(Numbers may have been plucked from the air)

Those numbers seem a couple of orders of magnitude out.
An ordonary car can accelerate around 2.2 m/s/s at that speed. In a couple of seconds that will make a 4.4 metre difference, about a car length.

Hold on, if you have m/s/s can’t you just cancel out the s and get m.

confused from Essendon

dv said:

Rule 303 said:

dv said:

There would be circumstances in which you can sensibly choose to accelerate to avoid a collision. I have no opinion on whether the average driver is equipped to make that choice.

I’m thinking: A vehicle moving at 17m/s applies maximal acceleration, which at this speed is 1.1m/s, the effect of which is to move the collision 33mm down the road. The speed increase has added 550N to the crash.








(Numbers may have been plucked from the air)

Those numbers seem a couple of orders of magnitude out.
An ordonary car can accelerate around 2.2 m/s/s at that speed. In a couple of seconds that will make a 4.4 metre difference, about a car length.

Putting aside the time lost in the driver’s reaction, the vehicle’s response, and the limits of traction, and that a couple of seconds is well and truly long enough for both drivers to take significant evasive action, I guess it’s worth saying that, in general, moving the impact backward on the vehicle is almost always going to improve safety.