Need help w/ physics question

[Mclovin]

Assume there is head-on wreck between two vehicles. One vehicle is going about 40 mph but the other vehicle is completely still. Assuming all else is equal, such as the size and weight of the two vehicles and the drivers, would the force experienced by both drivers be the same, and would the likelihood of injury be just as high for the person in the car standing still as it would for the person in the car going 40 mph? Also, what effect would it have if the car standing still has the brakes pressed down vs just sitting in neutral?

[mr.turbo]

you came to the right place

[Obvious Gimmick]

.

[HTexan]

Is this a data sufficiency question?

[Howard]

Assume there is head-on wreck between two vehicles. One vehicle is going about 40 mph but the other vehicle is completely still. Assuming all else is equal, such as the size and weight of the two vehicles and the drivers, would the force experienced by both drivers be the same, and would the likelihood of injury be just as high for the person in the car standing still as it would for the person in the car going 40 mph? Also, what effect would it have if the car standing still has the brakes pressed down vs just sitting in neutral?

If it is the same make/model the force on each car should be the same.
This is why you get wrecked if you run into a wall at 40 mph.
Believe it or not when a bug hits your windshield the force is identical for both.
The reason the bug gets smooshed is because it has so little mass compared to the car.

Now the only saving thing is what we call "impulse".
This is the force divided by the time it takes to stop.
The longer it takes to stop, the less force you feel at any one instant.
This is why crunch zones, padding and air bags help reduce impact injury.
If the sitting car is in neutral and free to roll it will increase the time to stop at the point of impact.
This reducing the impact force due to impulse forces.

Now, if you are standing in the car at impact, your body will be flown forward due to it's inertia.
The seat belt helps you remain strapped in the car and places the inertial forces on the belts.

Oh, if one car bounces off the other, this is known as an elastic collision.
The impact force is greater then one where they stick together at impact.

FYI< good question.

[OneMoreRep]

I think Howard is a Physics teacher, but I can be mistaken.

"1"

[mr.turbo]

the forces/effects are equal on both vehicles

the brakes would increase the forces applied to the cars during the collision in proportion to the friction at the tires/pavement

understanding what's going on with the drivers is a little more fussy

[El Diablo Blanco]

Depends if a Hebrew or Asian is driving.  Do they have loud music on?

[Wiggs]

If it is the same make/model the force on each car should be the same.
This is why you get wrecked if you run into a wall at 40 mph.
Believe it or not when a bug hits your windshield the force is identical for both.
The reason the bug gets smooshed is because it has so little mass compared to the car.

Now the only saving thing is what we call "impulse".
This is the force divided by the time it takes to stop.
The longer it takes to stop, the less force you feel at any one instant.
This is why crunch zones, padding and air bags help reduce impact injury.
If the sitting car is in neutral and free to roll it will increase the time to stop at the point of impact.
This reducing the impact force due to impulse forces.

Now, if you are standing in the car at impact, your body will be flown forward due to it's inertia.
The seat belt helps you remain strapped in the car and places the inertial forces on the belts.

Oh, if one car bounces off the other, this is known as an elastic collision.
The impact force is greater then one where they stick together at impact.

FYI< good question.

Amazing how you can be so intelligent in science and yet so ignorant in so many other things.

[SF1900]

Johnny Falcon will provide you with a thorough answer that also includes aspects of electricity and heme iron.

[SF1900]

Amazing how you can be so intelligent in science and yet so ignorant in so many other things.

Hes not really ignorant in other areas. He's only ignorant because in your subjective world he is wrong. But in his own subjective world he is correct. Its erroneous to call him ignorant because his worldviews do not coincide with yours.

Do some reading on Social Constructionism.

[Grape Ape]

Assume there is head-on wreck between two vehicles. One vehicle is going about 40 mph but the other vehicle is completely still. Assuming all else is equal, such as the size and weight of the two vehicles and the drivers, would the force experienced by both drivers be the same, and would the likelihood of injury be just as high for the person in the car standing still as it would for the person in the car going 40 mph? Also, what effect would it have if the car standing still has the brakes pressed down vs just sitting in neutral?

Are they bodybuilders?

[DroppingPlates]

Amazing how you can be so intelligent in science and yet so ignorant in so many other things.

Says the man who believes in the bible, aliens and other fairy tales...

[El Diablo Blanco]

Says the man who believes in the bible, aliens and other fairy tales...

[Wiggs]

Hes not really ignorant in other areas. He's only ignorant because in your subjective world he is wrong. But in his own subjective world he is correct. Its erroneous to call him ignorant because his worldviews do not coincide with yours.

Do some reading on Social Constructionism.

I don't subscribe to a European worldview so your books are mere entertainment and research material. He is ignorant. A wise fool.

[Mclovin]

If it is the same make/model the force on each car should be the same.
This is why you get wrecked if you run into a wall at 40 mph.
Believe it or not when a bug hits your windshield the force is identical for both.
The reason the bug gets smooshed is because it has so little mass compared to the car.

Now the only saving thing is what we call "impulse".
This is the force divided by the time it takes to stop.
The longer it takes to stop, the less force you feel at any one instant.
This is why crunch zones, padding and air bags help reduce impact injury.
If the sitting car is in neutral and free to roll it will increase the time to stop at the point of impact.
This reducing the impact force due to impulse forces.

Now, if you are standing in the car at impact, your body will be flown forward due to it's inertia.
The seat belt helps you remain strapped in the car and places the inertial forces on the belts.

Oh, if one car bounces off the other, this is known as an elastic collision.
The impact force is greater then one where they stick together at impact.

FYI< good question.

The part that is confusing me is that, on one hand, it seems like pressing the brakes would decrease the force for the car standing still bc the rate of deceleration (or acceleration backward) would be less, thereby reducing his chances of injury from his head snapping forward. But since the force is the same for both vehicles, that wouldn't make sense. I guess the question of driver injuries is more than just a simple matter of how much force is involved.

[Howard]

I think Howard is a Physics teacher, but I can be mistaken.

"1"

C'mon now, do you really think a regular poster in get big would have degrees in physics and teach it? get real.
I dropped out in 8th gr and work in a drill bit factory.

[Howard]

Amazing how you can be so RETARDED in science and yet so ignorant in so many other things.

fixed - I'm an all purpose retard .

[el numero uno]

Howard, is it true that a particle can be in 2 places at the same time (superposition)? Or Discovery Channel is bull$h1tting me?

[SF1900]

I don't subscribe to a European worldview so your books are mere entertainment and research material. He is ignorant. A wise fool.

That is fine. And he may subscribe to his own worldview, thus viewing your worldview as ignorant.

Goes both ways. Now, of course you're going to think you're right, and he is probably thinking the same thing.

[_bruce_]

Physics 
Yeah "Howard" - keep telling us about these artificial models when in reality it's the Rothchilds and their super computer(an overlocked Z80 supercalibrated to 6.66 gorillohertz) controlling every particle in this forsaken money-verse.

 

[ritch]

I failed grade 11 pysics.
How can I help?

[Howard]

The part that is confusing me is that, on one hand, it seems like pressing the brakes would decrease the force for the car standing still bc the rate of deceleration (or acceleration backward) would be less, thereby reducing his chances of injury from his head snapping forward. But since the force is the same for both vehicles, that wouldn't make sense. I guess the question of driver injuries is more than just a simple matter of how much force is involved.

The reason seat belts work is because they prevent the passenger from being thrown rapidly into something at impact.
The padding and air bags REDUCE the impact force you experience because they INCREASE the time it takes to stop.
Acceleration is any change in speed OR direction  divided by time.
The longer it takes to stop , the less acceleration ( or g forces) your body will experience.

Now try this basic demo for better understanding.
Hold up one hand, hold it rigid and punch it with the other.
Now repeat punching the same hand BUT, relax it and the arm of the punched hand.

Notice how when relaxed, the punched hand feels less force and is allowed to recoil and absorb some of the blow.

This is an old boxing defense trick known as originally as "roll with the punches".
Later Ali used it and called it the "rope a dope" defense.

[C-BuZz]

If it is the same make/model the force on each car should be the same.
This is why you get wrecked if you run into a wall at 40 mph.
Believe it or not when a bug hits your windshield the force is identical for both.
The reason the bug gets smooshed is because it has so little mass compared to the car.

Now the only saving thing is what we call "impulse".
This is the force divided by the time it takes to stop.
The longer it takes to stop, the less force you feel at any one instant.
This is why crunch zones, padding and air bags help reduce impact injury.
If the sitting car is in neutral and free to roll it will increase the time to stop at the point of impact.
This reducing the impact force due to impulse forces.

Now, if you are standing in the car at impact, your body will be flown forward due to it's inertia.
The seat belt helps you remain strapped in the car and places the inertial forces on the belts.

Oh, if one car bounces off the other, this is known as an elastic collision.
The impact force is greater then one where they stick together at impact.

FYI< good question.

Your body won't be flu g forward. You will fall far wards due  vehicle moving backwards. IE: rug being pulled out from under your feet.

[tommywishbone]

you came to the right place

Haha.   Indeed he did!