Collision Physics ?!?!

[Secki]

Ok any physics genius's or Crash Investigation fanatics might be able to help with this one. The other halves old mans rodeo was slammed head on by a SSS Pulsar. Rodeo was parked, and weighs approx 2 tonnes full of tools. Nissan Pulsar SSS approx 1.3 tonnes. Rodeo was pushed about 5 metres and the SSS bounced back from the collison. What i was wondering is what sort of speeds this SSS would have to have been doing to move a 2 Tonne Rodeo 5 metres?

[nicko]

alot of speed. but there are TOO many factors that can contribute. road surface incline angle of impact etc. but yes the sss would have been hooking

[stocky]

i tried. got my physics book out here lol. too many factors missing to work it out.

[jules]

it's indeterminate, unless you know the frictional force acting to slow the car down.

cops often use deformation of the vehicle to calculate impact speed.

[azkwazere]

auto or manual?
Hand Brake on or off?
In gear or out of gear?
On a slope or Flat?
Road surface smooth or tarmac style?
Strong winds or not?
Road wet or try?
Hot day or cold?
Perfect head on or with a slight angle?

you could work out a speed but it would be without serious accuracy... like not even ball park sorta thing..

aZk.

[stocky]

i call for a reenactment. anyone got an sss and a rodeo i can borrow for a couple of days? will be returned undamaged....promise

[azkwazere]

shotgun helping in the name of science!!!

azk.

[crazyspoon05]

i call for a reenactment. anyone got an sss and a rodeo i can borrow for a couple of days? will be returned undamaged....promise

I've got a Pulsar you can borrow, however in it's current state getting up to a speed near that impact speed could take a while....

[Secki]

Those SSS 2.0litre were a hot little car, it was 4 am, flat street, dry conditions, and rough bitchumen! will try get some pics up ! he reckons he was doing 40-50km and fell asleep at the wheel lol !

Also with the young dudes insurance they would have to replace my girls dads car as is ? ie with bullbar, winch, and such ? not just pay him out for the base model market value with no accessoires wouldnt they? he is thinking of also suing for loss off income as its his work rig.

[commsirac]

Yes, there are a lot of variables that can stop an exact answer being arrived at or to be used as an excuse to do anything.

My estimate is made using the following deductions:

Gradient of road insignificant since it wasnt mentioned. (Steepness of road will have little effect on the answer, except if gradient of more than 5%, will affect how hard handbrake had been applied)
Handbrake applied firmly enough to stop secure on level ground and car left in gear(assuming its a manual since rodeo), rear wheels wont lock up in collision. If they did lock up, friction force would be ~0.4 x weight of vehicle......so estimate of ~0.1 x weight of vehicle. It would be possible to see if the wheels had remained locked by evidence of tyre marks from where the rodeo moved and single abrasion spot on tyre. One grey area is was there witnesses to the crash, did the rodeo actually move 5m forwards? or was the nissan found 5m behind it. I seriously doubt whether the nissan would move backwards from the actual initial position of impact. Assuming that the nissan was perhaps found 5m behind and moved ~ 1m forwards.

Hence answer: 55km/h+/-10

[Secki]

Rodeo was in gear with hand brake on and was moved about 4.5 metres, oh well this has been a fun topic anyway!

[Emackulation]

I did the calculations, the SSS was traveling at 110-112km/h. Hope this helps.

[Jesterarts]

^^^ keeping in mind that would be the speed @ the instance of impact.

Which brings up a few questions.

1. How the bugger do you fall asleep @ 110kmph??

2. Was there skid marks from the pulsar??

and if so

3. How fast was he going before he hit the brakes?!?

[Not_An_Abba_Fan]

Ring CSI...

[commsirac]

One fact that could be supplied, did the driver of the pulsar survive?
It is still lineball, even with airbags that a head on at 60kmh(with same sized car) or collision at same speed with fixed object is survivable.
Although hitting a 2 tonne vehicle that is not fixed to the ground is preferable than hitting a fixed object, if the collision was at 100-110km/h and the rodeowas free to move with minimal resistance the impact for the pulsar driver would still be greater than a 60kmh head on, not survivable. Given that the vehicle wasnt free to move easily, the impact forces would have been considerably higher.

[albert5268]

I just calculated it out to be around 12.81 kmh therefore it is a conspiracy

[stocky]

I just calculated it out to be around 12.81 kmh therefore it is a conspiracy

think about how slow that is for a second. the rodeo wouldnt budge if it got hit that slow

One fact that could be supplied, did the driver of the pulsar survive?
.

he is thinking of also suing for loss off income as its his work rig.

im sure hed be alive. i doubt he wants to sue a dead a guy

[Emackulation]

You do realize my above post was utter rubbish LOL.

[commsirac]

think about how slow that is for a second. the rodeo wouldnt budge if it got hit that slow



im sure hed be alive. i doubt he wants to sue a dead a guy

Good point, unless he is suing the owner of the car who is not the driver or the estate of the deceased. Hence Id definitely rule out anything greater than 60km/h and stand by my earlier initial estimate.

12km/h, enough to do more than a couple of thousand dollars worth and move the rodeo.

[mar-d-mac]

I did the calculations, the SSS was traveling at 110-112km/h. Hope this helps.

at this speed - SSS driver would be a statistic by now..

[commsirac]

You do realize my above post was utter rubbish LOL.

Yes, having read previous your posts I was aware that there was little chance that you would really have any substance behind such a claim, but wasnt so sure that you actually believed what you were saying or not, as some did take your rubbish suggestion as feasible.

[jules]

what sort of tools were in the rodeo? what pressure were the tyres inflated to?

[Not_An_Abba_Fan]

Did the Pulsar have fluffy dice?

[Emackulation]

Yes, having read previous your posts I was aware that there was little chance that you would really have any substance behind such a claim, but wasnt so sure that you actually believed what you were saying or not, as some did take your rubbish suggestion as feasible.

Do you wunna go to dinner some time?

[azkwazere]

what colour was each vechical?

aZk.