Physics Question..

WorshipJesus · 12-04-2011, 09:17 PM

How much energy (mph) does it take for a Chevy Impala (3,555 lbs) to push a For Ranger (3,050 lbs) 30-40 feet if it tbones the Ranger?

I was in a pretty bad accident. Someone tboned my Ranger pushed it 30-40 sideways. I was just wondering if anybody knows how to find out approximately how fast he was going.

**thesteve** · 12-04-2011, 10:07 PM

I can tell you from a bit of googling that this physics is probably on the complicated side for non-physic majors or non-accident re-constructors.

**DaGeek** · 12-05-2011, 07:31 AM

Regardless of the answer to this question, which I have no idea how to determine, I'm glad that you're okay!

**tmlfan123** · 12-05-2011, 07:52 AM

Quote:

Originally Posted by WorshipJesus

How much energy (mph) does it take for a Chevy Impala (3,555 lbs) to push a For Ranger (3,050 lbs) 30-40 feet if it tbones the Ranger?

I was in a pretty bad accident. Someone tboned my Ranger pushed it 30-40 sideways. I was just wondering if anybody knows how to find out approximately how fast he was going.

There are a few too many unknowns here to make any kind of accurate prediction. Conservation of force and conservation of momentum equations would work in this case, but you would likely need a more accurate measurement for distance from impact to full stop, as well as coefficient of friction between cars and the ground (which is further complicated by when he started to brake and whether he continued/was able to slam on the brakes throughout the collision, and whether all wheels were in contact with the ground for the full duration of the accident). Another couple of factors include whether the impact was made at a perfect 90 degrees, and which part of your car was hit (perfectly in the center of mass of your vehicle, or to the side causing rotation and consequently constantly changing values for kinetic friction coefficients). All that to say, to get any kind of accurate result, you're going to need more information. I could do a very, very basic numbers crunch for a ballpark figure, but my feeling is that I could fairly easily be off by 7-10 mph and I'm guessing that would render the result fairly useless.

Aside from all that, glad you're well enough to even be making this post - that's a really serious accident.

Plexi8759 · 12-05-2011, 07:58 AM

Man this takes me back to my physics class of which I don't remember much of anything except that I really liked the class. Glad your ok as well!

**Ted Logan** · 12-05-2011, 08:43 AM

I think we just have to play Enrico Fermi and make estimations.

Given the variables you've supplied, and assuming it was a perfect T-Bone (the cars were exactly perpendicular), and assuming approximately 15% of the force was absorbed by the crumpling of your side panels, and assuming you had good tires with good contact zones which skidded rather than skipped, and assuming a paved road rather than gravel or asphalt, I think it works to something like this:

The amount of force applied to your Ranger > the amount of force required to crush a taco shell
The amount of force applied to your Ranger < the amount of force required to destroy an asteroid the size of Texas if you're Bruce Willis

I'm 99.9999997% confident that this range includes the amount of force applied to your Ranger.

Also, I'm glad you're okay enough to be typing on CGR!

Vanguard17 · 04-11-2012, 06:28 AM

I'm glad you're okay. I wish I could figure that out for you.

Vanguard17 · 04-23-2012, 05:27 PM

Quote:

Originally Posted by WorshipJesus

How much energy (mph) does it take for a Chevy Impala (3,555 lbs) to push a For Ranger (3,050 lbs) 30-40 feet if it tbones the Ranger?

I was in a pretty bad accident. Someone tboned my Ranger pushed it 30-40 sideways. I was just wondering if anybody knows how to find out approximately how fast he was going.

Inadequate amount of information. I have to know how long it took him to stop.