head on GMR

glhs837

glhs837

Power with Control
itsbob said:
Actually not..

The damage from a head on collision of two cars traveling 30 MPH is the same as ONE car hitting a wall at 30 MPH.. or 50.. or 60..

There is no increase in damage because there are two cars v one car and a wall..
Click to expand...



I was saying that the one car going 30 hitting another going 30 is the same as hitting a wall at 60. but should have chosen parked car due to structural differences with crumple zones and all:))

The total amount of energy involved between the two moving objects is added, correct? So, if you will allow me a parked car vs a car moving at 30mph, are we agreed that there is a lot more energy involved in hitting a car coming at you at 30 than hitting a parked car? your car of course has no extra energy, but that other car is bringing it's own energy to the collision.
 
itsbob

itsbob

I bowl overhand
SoMDGirl42 said:
Question for you.

Since you used "is" present tense first, shouldn't you use "is" present tense second instead of "was" which is past tense?

Serious question here.

The very next sentence in the article was even worse but there was no play on words, just REALLY bad grammar

or

The very next sentence in the article is even worse but there is no play on words, just REALLY bad grammar
Click to expand...


I don't write for a newsite or a publication of any kind, and don't assume to be a perfect writer.


However, I would assume somebody that does work/write for a news service, or an online publication to at least have more better skills than I..
 
itsbob

itsbob

I bowl overhand
glhs837 said:
I was saying that the one car going 30 hitting another going 30 is the same as hitting a wall at 60. but should have chosen parked car due to structural differences with crumple zones and all:))

The total amount of energy involved between the two moving objects is added, correct? So, if you will allow me a parked car vs a car moving at 30mph, are we agreed that there is a lot more energy involved in hitting a car coming at you at 30 than hitting a parked car? your car of course has no extra energy, but that other car is bringing it's own energy to the collision.
Click to expand...

NOPE..

Two cars going 45 MPH hit head on, there damage is exactly the same as a single car going 45 MPH into a concrete stationary wall..

From that I would assume if a car traveling 35 hit a parked car their damage would be significantly less than a car hitting a concrete wall at 35.. In fact would closer to a car going 17.5 MPG into a concrete wall..

The force of impact is shared between two similar structures so you can add the speed of the two, and divide by two.

Two cars going 35 MPH... 35+35 = 70 divided by 2 = 35

(using addition makes it easier when the two vehicles are traveling at different speeds)

A concrete wall suffers no damage (or minimal damage) so the vehicle hitting the wall takes ALL the damage.. Divide by 1...

One car into a wall at 35 MPH 35 + 0 = 35 divided by 1 = 35
 
Last edited:
SoMDGirl42

SoMDGirl42

Well-Known Member
itsbob said:
I don't write for a newsite or a publication of any kind, and don't assume to be a perfect writer.


However, I would assume somebody that does work/write for a news service, or an online publication to at least have more better skills than I..
Click to expand...

I don't either either, but you didn't answer the question.
 
itsbob

itsbob

I bowl overhand
SoMDGirl42 said:
Question for you.

Since you used "is" present tense first, shouldn't you use "is" present tense second instead of "was" which is past tense?

Serious question here.

The very next sentence in the article was even worse but there was no play on words, just REALLY bad grammar

or

The very next sentence in the article is even worse but there is no play on words, just REALLY bad grammar
Click to expand...

BUT (I know, bad form) not really true..

Tha sentence in the article was bad, and still is bad..

When I originally looked at it (as in looked, in the past) there was no play on words..

The sentense is still bad, and there was no play on words when I read it.
 
MMDad

MMDad

Lem Putt
glhs837 said:
I was saying that the one car going 30 hitting another going 30 is the same as hitting a wall at 60. but should have chosen parked car due to structural differences with crumple zones and all:))

The total amount of energy involved between the two moving objects is added, correct? So, if you will allow me a parked car vs a car moving at 30mph, are we agreed that there is a lot more energy involved in hitting a car coming at you at 30 than hitting a parked car? your car of course has no extra energy, but that other car is bringing it's own energy to the collision.
Click to expand...

The total energy of the collision is absorbed by the two cars. When hitting a wall, almost all of the energy is absorbed by the car and little by the wall.

The total energy is (mass * speed) + (mass * speed). Assuming similar vehicles, each will absorb about half of the energy. So a head-on where each is doing 30 is not the same as a hitting a wall at 60.

If you hit a snowplow, the energy will be absorbed by both vehicles, but the unequal mass and crumple means the car will absorb far more energy.
 
SoMDGirl42

SoMDGirl42

Well-Known Member
itsbob said:
BUT (I know, bad form) not really true..

Tha sentence in the article was bad, and still is bad..

When I originally looked at it (as in looked, in the past) there was no play on words..

The sentense is still bad, and there was no play on words when I read it.
Click to expand...

keep your day job :killingme
 
glhs837

glhs837

Power with Control
Guys, I dumped the wall and replaced with a parked car, okay:) I admit the wall was a bad choice. So, given that, are you saying that hitting an a car oncoming at 35 would result in the same damage as hitting a parked car at 35?
 
SoMDGirl42

SoMDGirl42

Well-Known Member
itsbob

itsbob

I bowl overhand
kwillia said:
If a car traveling at 70 mph and crashes head-on with another car traveling at 70 mph, does that make it equivalent to hitting something stationary at 140 mph?


Hmmm... everybody on this site seems to be saying "yep".

Read more: | Answerbag If a car traveling at 70 mph and crashes head-on with another car traveling at 70 mph, does that make it equivalent to hitting something stationary at 140 mph? | Answerbag
Click to expand...

Nope.. the damage is shared between the two vehicles at close to equivalent damage. Add their speed and divide by two.

Run a car into a concrete wall at that speed and that's the amount of damage that can be expected.

Two cars traveling 70 MPH will have the same amount of damage as a single car hitting a concrete wall at 70 MPH.
 
SoMDGirl42

SoMDGirl42

Well-Known Member
glhs837 said:
Guys, I dumped the wall and replaced with a parked car, okay:) I admit the wall was a bad choice. So, given that, are you saying that hitting an a car oncoming at 35 would result in the same damage as hitting a parked car at 35?
Click to expand...

no, the parked car is not moving.
 
kwillia

kwillia

n/a
Okay.. I don't trust itsboob, but I do trust Mythbusters...:lmao:

MythBusters Episode 143: Mythssion Control

Two cars crashing into each other at 50 mph will result in the same damage (for each car) as a single car hitting a wall at 50 mph.
confirmed

In their small scale tests, the Mythbusters compressed clay at 1x and 2x speeds. Their results showed that two objects hitting each other at 1x speed will cause 1x damage. In their full scale tests, the Mythbusters crashed two cars into a wall at 50 and 100 mph as references. They then had two cars going at 50 mph collide into each other. After surveying the results, it was clear that the two cars suffered damage identical to the car that crashed into the wall at 50 mph. The Mythbusters explained that was possible through Newton’s third law of motion. Although the total force was doubled by having two cars, that force also had to be divided between both cars during the crash.
 
itsbob

itsbob

I bowl overhand
kwillia said:
If a car traveling at 70 mph and crashes head-on with another car traveling at 70 mph, does that make it equivalent to hitting something stationary at 140 mph?


Hmmm... everybody on this site seems to be saying "yep".

Read more: | Answerbag If a car traveling at 70 mph and crashes head-on with another car traveling at 70 mph, does that make it equivalent to hitting something stationary at 140 mph? | Answerbag
Click to expand...

Not anymore..

Somebody with more than 2 braincells in their head actually answered it correctly..

I LOVE the guy that's trying to sound like Einstein..

Classically, and for the purpose of your answer, yes.

At higher velocities though, you'd NEED to use lorentzian transforms to convert between the two frames. In this case, you'd get about 139.99999999 mph, but it comes in important later on.

E.g. 0.5c vs 0.5c would be the equivalent of going into something at about 0.79c or so. I'd have to actually do the calc to be sure but its in that area
Click to expand...
 
A

abcxyz

New Member
itsbob said:
NOPE..

Two cars going 45 MPH hit head on, there damage is exactly the same as a single car going 45 MPH into a concrete stationary wall..

From that I would assume if a car traveling 35 hit a parked car their damage would be significantly less than a car hitting a concrete wall at 35.. In fact would closer to a car going 17.5 MPG into a concrete wall..

The force of impact is shared between two similar structures so you can add the speed of the two, and divide by two.

Two cars going 35 MPH... 35+35 = 70 divided by 2 = 35

(using addition makes it easier when the two vehicles are traveling at different speeds)

A concrete wall suffers no damage (or minimal damage) so the vehicle hitting the wall takes ALL the damage.. Divide by 1...

One car into a wall at 35 MPH 35 + 0 = 35 divided by 1 = 35
Click to expand...

I disagree, however what I really wanted to know is how MPG factors in to this?

(ps- hold one hand in front of you and wind up and smack it with your other hand. Now swing both hands (clapping). See which one hurts more... (clapping does)).
 
You must log in or register to reply here.
Top