Tacoma: 1, Death: 0

I bet it was because he stood on the brake pretty hard right before impact? Ouch, glad they survived in pretty good shape.

 

Lol it is. If you were in one of the vehicles traveling towards the other vehicle and both were going the same speed of 60 mph, the closing speed would be 120 mph.
Here's the difference between just heading towards the vehicle and actually hitting it:
Let's say a vehicle weighing 5000 lbs going 60 mph hits something that cannot move or compress, like a thick concrete wall. The wall will not absorb any of the kinetic energy so the vehicle has to absorb all the energy of the crash.
Now let's say the same vehicle is approaching a vehicle that weighs exactly the same as theirs and both are going 60 mph. They have a perfect head on collision. Both vehicles now share in absorbing the kinetic energy from traveling 60 mph. They are both the same mass and the same velocity so they each absorb 60 mph worth of energy, not 120 mph.
Now, if you hit a stationary Taco at 60 mph, it would not be the same as hitting a concrete wall or hitting a Taco directly at 60 mph. That stationary Taco would absorb a lot of energy and be knocked backwards. Depending on the hit, it would be like hitting another Taco at 40 or 30 mph. Remember the vehicles "share" the kinetic energy in an accident. A concrete wall does not share, which is why they are used in crash tests instead of hitting another vehicle.
And lastly, usually the driver of the heavier vehicle absorbs less energy and has less damage.

 

And that's with an unmodified body mount.

 

I'm pretty sure I saw your buddy in that Taco late January between Beaver and Parowan. Cali plates, black taco, stock wheels and the GFC.....can't be two of them. January 30th to be exact. I was coming back from Idaho.

I15 is crazy...80 mph speed limit. lots of big rigs and touristas....glad he's okay.

 

There is a ridiculous video captured by a webcam on car where an SUV a few cars ahed of them got hit head on by a tractor trailer truck. It is pretty damn violent. The SUV essentially disintegrated and the tractor trailer truck kept going.

 

Wow, glad no one was hurt worse!

 

Verdict is out, yes he did have a CMC.

 

Apples and oranges there. Two tacos colliding head on with both going 60mph would essentially be equivalent to one taco going 120 mph hitting a stationary taco head on.

 

not quite, the relation to speed is not a linear curve 120mph is not twice the energy as 60 mph, its 4 times the energy, because the equation is mass times velocity squared, not just mass times velocity. A 1 pound mass at 60 feet per second has 3600 foot pounds of energy. A 1 pound mass travelling 120 feet per second has 14,400 foot pounds of energy.

 

You’re correct. I should have done the math.

 

Glad they made it out alive!

 

First of all, glad they are ok, that's probably one of the worst hits I've seen on here.
Aren't vehicles designed to basically self destruct (around the passenger compartment) in crashes like this to absorb as much energy as they can? Putting something "more solid" up from could actually be worse in a collision, but I could be wrong...

 

Thats really cool. Seems to me it did a really great job at protecting the occupants. I think at this point, if anyone wanted to play devils advocate and say the CMC led to a broken passenger foot, I'd say it still did its job, and if thats all that came of an accident of that severity, they're still extremely blessed.

 

Exactly. Hate to be "that guy", but the underlying discussion with relevant calculations should be using collision (derivations of elastic and inelastic) equations (m1iv1i + m2iv2i = m1fv1f + m2fv2f) to determine usable force dispersal through both vehicles - these would give tangible numbers to show the amount of energy being distributed here and "where" it's going. Kinetic energy is just a marker (like acceleration, velocity, mass, etc.) used to quantify physical objects moving in space - once collisions are involved there are different equations and variables required.

That being said, it's a very impressive display of engineering here (with the implementation of crumple/crash zones in the Tacoma structure used to mitigate occupant trauma) that with all the forces involved in this accident and the severity (based on pics) of the collision that there is "only" a broken foot and some stitches as the outcome. The engineering and design used to "slow" the negative acceleration (deceleration) for the driver and passenger is something to behold, and something that had we seen this same wreck 10-15 years ago would likely have had a different outcome.

 

You are even more correct lol. It’s not a simple matter of calculating kenetic energy as I looked into it more. Conservation of momentum, elastic collisions vs inelastic, energy dissipated in the form of heat and sound all factor into a collision.
http://hyperphysics.phy-astr.gsu.edu/hbase/col1d.html#:~:text=Initial kinetic energy KE = 1,make possible such a collision

https://www.physicsclassroom.com/mmedia/momentum/2di.cfm

 

Sort of. Another vehicle could be used in a crash test, but then you'd be introducing a whole additional set of variables to the force equations, making the calculations unnecessarily more complex. The concrete/steel barrier is used because it acts as a known constant in the equations and is repeatable, so that the majority of forces in the collision are acting on the vehicle itself, and those forces can more easily be measured and observed and used for subsequent data gathering to design "better" later (or to tell the government "see, ours is XX better than our competitors").

 

There is also a reason crash tests stop at 40 mph...

 

Yeah, isn't like x% less survivability per MPH over 40MPH or something?

 

You will feel the decel on impact of around 80g's. In addition, your body will feel the equivalent of around 20K lbs evenly distributed for around a quarter second.
Yeah, chances of surviving are slim.
People need to remember that even when the outside of your body stops, the insides, like your brain, heart, liver, etc will continue until they slam up against the inside front of you. So even though you could not have a scratch, the internal trauma could kill you.