MythBusters - Crash Force - awesome test

trev0006 · Post by **trev0006** » Tue May 18, 2010 12:13 pm

Video - MythBusters - Crash Force

Mythbusters crew decided to revisit an old myth that was drawing the ire of the show's fans for quite some time. And it's sure to be an interesting topic to automotive enthusiasts.

When two cars collide, each traveling 50 miles per hour, does the resulting force equal one car hitting an immovable object at 100 miles per hour?

It seems like such simple physics, no? But don't forget Newton's third law. To quote the great Wikipedia of knowledge, "Whenever a first body exerts a force F on a second body, the second body exerts a force −F on the first body. F and −F are equal in magnitude and opposite in direction." Or, more simply, for every action there is an equal and opposite reaction.

milehighXR · Post by **milehighXR** » Tue May 18, 2010 12:48 pm

Watching them destroy stuff never gets old, does it...

Post by **DPDISXR4Ti** » Tue May 18, 2010 1:41 pm

Very interesting. How many driver's ed teachers have been providing bad info over the years???

Post by **John Brennan** » Tue May 18, 2010 1:46 pm

Mine did. It never made any sense to me then, either.

milehighXR · Post by **milehighXR** » Tue May 18, 2010 4:04 pm

Don't NHTSA, and IIHS spread the same misconception?

Post by **Ed Lijewski** » Tue May 18, 2010 4:07 pm

Guesses on the make/model of that OrangeCrusher in the first vid?

Daewoo Nubira.

YMMV

milehighXR · Post by **milehighXR** » Tue May 18, 2010 6:10 pm

I noticed that both cars were Daewoos. Not many around here, and those that are I think were Cali transplants.

MerkurScorpio · Post by **MerkurScorpio** » Sat May 22, 2010 7:38 pm

Very interesting segment.

By the way, there's a possibility a Scorpio might show up on MythBusters one of these days, in case you haven't heard.

Firefox · Post by **Firefox** » Sat May 22, 2010 11:31 pm

It's all fun and games until someone looses an XR4Ti. Or a Scorpio, as the case may be.

pyropete125 · Post by **pyropete125** » Fri Jun 18, 2010 5:16 pm

whats the top gear car brand that pianos drop on all the time? i hope they never do that the merkurs, lol.

FASTBACK69 · Post by **FASTBACK69** » Sat Jun 19, 2010 5:46 am

That would be the Morris Marina. Jeremy loves fast Fords so Merkur's and Sierra's are safe.

MerlinMerkur · Post by **MerlinMerkur** » Thu Jul 22, 2010 11:13 pm

I won't presume to master the principles to decide this matter but I will say these 3 things:

1) Mythbusters is AWESOME (even though they miss things time to time)

2) I wouldn't wanna be between the two said vehicles because.. im pretty sure destroyed and destroyedX2 are both destroyed

Destroyeder?

3) I have been mythbusting ever since I figured out that cats really DONT land on their feet every time WHAHhahahahahahhaha!!!
Just kidding ASPCAian keep your lawyers pants on.

MerlinMerkur · Post by **MerlinMerkur** » Fri Jul 23, 2010 12:38 am

Agh I shoulda watched the video first but I have some ideas that Mythbusters seems to have skirted over in their test variables, sigh** (come on guys shape up your losing your touch)

In the comparison of the 2 forces ONE-the immovable wall with the car impacting it at 100mph, and TWO-the two cars colliding at 50 mph opposing, the reason the data does not match (as their experiment suggests) is because the wall did not absorb ANY of the force exerted against it, so the car impacting it took the full brunt of 2500lbs at 100mph, whereas with the two cars hitting each other each car absorbed its own energy by buckling and crushing itself against the other (cancelling each other is not quite the same). IN other words, the opposing car functioned essentially the same as a wall only at 50mph, and so each car took 50mph worth of damage. Even the government goons know this because they put those water barrels in front of guard rails so people dont split their cars in half when they hit them. The two cars crashing into each other is really almost two experiments independently in progress at the same time, only using the others "circular reasoning data!" as a constant variable (because its opposing equal force makes it into a "wall" even though its NOT a wall because it crushes and a wall does not. Slam a 2500lb wall traveling at 50 mph into that 2500lb car traveling at 50mph if you want to see what I mean. It will show 100mph crushing.

And remember, the question wasn't necessarily visible damage to the car, but rather force applied resulting in an amount of damage visible.
"When two cars collide, each traveling 50 miles per hour, does the resulting force equal one car hitting an immovable object at 100 miles per hour?"
Just rereading the question you can see the problem with testing it, because the opposing car again is NOT an immovable object, but rather adds a whole nutha set of variables to the equation because it squishes too, it absorbs that extra 50mph of crushing force that WOULD normally show on the other car by crunching ironically... equally in the "opposite" direction.
Man over-thinking crap is just too much fun.

IF you really wanted to see if the opposing forces
"cancel each other" you would need to use items that do not crush, but rather both transfer all or most of their kinetic energy into the opposing force.

SO Im sending MythB's an email, tell em they needa run this one again with better variables that take out the "double crush" factor!