Have you guys noticed?

[Howard]

Large car vs large car and small car vs small car, injuries in each?

 

[exdeath]

Someone here needs to take a high school physics course and learn about conservation of momentum to understand that a smaller vehicle is going to get man handled by a much a larger vehicle, safety design considerations notwithstanding. Not to even mention there is less mass and materials to absorb and dissipate the energy and that kinetic energy is a square of velocity.

Btw you can make a small light car that is indestructible in a high speed collision with a heavier vehicle with modern materials, but it would be even *more* of a death trap for the occupants. The "welding" and "fabrication" have nothing to do with it.

http://www.glenbrook.k12.il.us...ss/momentum/u4l2b.html

See questions 2 and 3.

 

[fleabag]

Originally posted by: exdeath
Someone here needs to take a high school physics course and learn about conservation of momentum to understand that a smaller vehicle is going to get man handled by a much a larger vehicle, safety design considerations notwithstanding. Not to even mention there is less mass and materials to absorb and dissipate the energy and that kinetic energy is a square of velocity.

Btw you can make a small light car that is indestructible in a high speed collision with a heavier vehicle with modern materials, but it would be even *more* of a death trap for the occupants. The "welding" and "fabrication" have nothing to do with it.

http://www.glenbrook.k12.il.us...ss/momentum/u4l2b.html

See questions 2 and 3.

This is a somewhat irrelevant post. For one thing a larger vehicle isn't better because it can absorb and dissipate more energy because it HAS more energy to dissipate in the first place. A Volvo 240 is far safer in a single vehicle collision (such as with a brick wall) or in a "kenetic sense" than a semi truck. Understand what I'm getting at now? Yet with your logic, you'd always want to be driving a semi truck "because it is bigger and somehow has more materials to absorb and dissipate energy"....

Originally posted by: Howard
Large car vs large car and small car vs small car, injuries in each?

You SEEM to be understanding what I'm talking about, unfortunately you posted a sentence fragment and I'm not sure what exactly you're talking about.

 

[Howard]

I don't even know myself, sometimes.

What I want to know is whether it's safer (by whatever metric) for passengers to be in a collision where the cars involved are large ones rather than small ones - no size disparities.

 

[exdeath]

Originally posted by: fleabag

Originally posted by: exdeath
Someone here needs to take a high school physics course and learn about conservation of momentum to understand that a smaller vehicle is going to get man handled by a much a larger vehicle, safety design considerations notwithstanding. Not to even mention there is less mass and materials to absorb and dissipate the energy and that kinetic energy is a square of velocity.

Btw you can make a small light car that is indestructible in a high speed collision with a heavier vehicle with modern materials, but it would be even *more* of a death trap for the occupants. The "welding" and "fabrication" have nothing to do with it.

http://www.glenbrook.k12.il.us...ss/momentum/u4l2b.html

See questions 2 and 3.

This is a somewhat irrelevant post. For one thing a larger vehicle isn't better because it can absorb and dissipate more energy because it HAS more energy to dissipate in the first place. A Volvo 240 is far safer in a single vehicle collision (such as with a brick wall) or in a "kenetic sense" than a semi truck. Understand what I'm getting at now? Yet with your logic, you'd always want to be driving a semi truck "because it is bigger and somehow has more materials to absorb and dissipate energy"....

Originally posted by: Howard
Large car vs large car and small car vs small car, injuries in each?

You SEEM to be understanding what I'm talking about, unfortunately you posted a sentence fragment and I'm not sure what exactly you're talking about.

Hit a brick wall at 100 mph, do you want to be in a semi or a VW bug?

 

[fleabag]

Originally posted by: exdeath

Originally posted by: fleabag

Originally posted by: exdeath
Someone here needs to take a high school physics course and learn about conservation of momentum to understand that a smaller vehicle is going to get man handled by a much a larger vehicle, safety design considerations notwithstanding. Not to even mention there is less mass and materials to absorb and dissipate the energy and that kinetic energy is a square of velocity.

Btw you can make a small light car that is indestructible in a high speed collision with a heavier vehicle with modern materials, but it would be even *more* of a death trap for the occupants. The "welding" and "fabrication" have nothing to do with it.

http://www.glenbrook.k12.il.us...ss/momentum/u4l2b.html

See questions 2 and 3.

This is a somewhat irrelevant post. For one thing a larger vehicle isn't better because it can absorb and dissipate more energy because it HAS more energy to dissipate in the first place. A Volvo 240 is far safer in a single vehicle collision (such as with a brick wall) or in a "kenetic sense" than a semi truck. Understand what I'm getting at now? Yet with your logic, you'd always want to be driving a semi truck "because it is bigger and somehow has more materials to absorb and dissipate energy"....

Originally posted by: Howard
Large car vs large car and small car vs small car, injuries in each?

You SEEM to be understanding what I'm talking about, unfortunately you posted a sentence fragment and I'm not sure what exactly you're talking about.

Hit a brick wall at 100 mph, do you want to be in a semi or a VW bug?

VW Bug, less crash energy.

Originally posted by: Howard
I don't even know myself, sometimes.

What I want to know is whether it's safer (by whatever metric) for passengers to be in a collision where the cars involved are large ones rather than small ones - no size disparities.

Depending on the engineering, which was my entire point. A poorly engineered large car will be so much more unsafe for its passengers in a collision with another large car or brick wall than a decently engineered small car in a collision with another small car or brick wall.


Edit: Here are some more crash test ratings...
http://www.safecarguide.com/exp/archive/archive.htm
This one has the one of the Chevrolet Suburban 1987 which recieved 1 star for driver and 3 for passenger.

 

[exdeath]

Originally posted by: fleabag

VW Bug, less crash energy.

Somebody failed to research conservation of momentum. It has nothing to do with total energy. The car is absorbing the energy of the collision, not you.

It has to do with the fact that in a VW Bug, the wall will cause a greater acceleration on the car. In the big truck, it is the truck that will not budge much, while the wall is accelerated.

It is the rapid change in acceleration that hurts your body in a collision. The total force of collision is the same for both the small and the large object. What causes whiplash and ruptured organs for example, is the sudden reversal of acceleration in a very short time. Knowing that the force is the same for both objects, and that acceleration is what is responsible for injury, what factor can you change in your vehicle to lower the acceleration you feel on impact, and thus reduce your chances of injury? Hint: F=ma.

Lets try it again:

When driving very fast over a speed bump, which do you feel a greater bump and are more likely to be tossed around and get bruised: in a VW Bug, or a semi truck?

Also note that sheet metal in cars is designed to buckle on collision for the purpose of slowing down the change in acceleration and spreading it out so as to dampen the peak impulse. Also note that the vehicle of greater mass is naturally going to have more and heavier sheet metal to bend to this effect. Remember, the force is the same for both objects in a collision.

 

[fleabag]

Originally posted by: exdeath

Originally posted by: fleabag

VW Bug, less crash energy.

Somebody failed to research conservation of momentum. It has nothing to do with total energy. The car is absorbing the energy of the collision, not you.

It has to do with the fact that in a VW Bug, the wall will cause a greater acceleration on the car. In the big truck, it is the truck that will not budge much, while the wall is accelerated.

It is the rapid change in acceleration that hurts your body in a collision. The total force of collision is the same for both the small and the large object. What causes whiplash and ruptured organs for example, is the sudden reversal of acceleration in a very short time. Knowing that the force is the same for both objects, and that acceleration is what is responsible for injury, what factor can you change in your vehicle to lower the acceleration you feel on impact, and thus reduce your chances of injury? Hint: F=ma.

Lets try it again:

When driving very fast over a speed bump, which do you feel a greater bump and are more likely to be tossed around and get bruised: in a VW Bug, or a semi truck?

Also note that sheet metal in cars is designed to buckle on collision for the purpose of slowing down the change in acceleration and spreading it out so as to dampen the peak impulse. Also note that the vehicle of greater mass is naturally going to have more and heavier sheet metal to bend to this effect. Remember, the force is the same for both objects in a collision.

What is to say the larger vehicle will be able to dissipate more of its energy over the smaller vehicle? You're forgetting that a lot of bigger vehicles such as SUVs are body on frame, and in a crash, that frame isn't going to dissipate ANY energy, I know because I've seen some gnarly trucks after a crash with the frame only slightly bent. According to the NHTSA, bigger vehicles crash harder which is why crash test ratings aren't directly comparable between different sizes, because it can be harder for a large vehicle to dissipate its energy over a smaller one.

The most ideal vehicle in a crash is one made of very light but strong materials spanning over a "long" distance. This is one reason why the Yaris would be less safe than a Mercedes CLK, because the CLK has a longer hood and the Yaris as a shorter hood. In fact, one reason why the Volvo 240 has such a long trunk and hood is because it was designed with crash safety in mind and they didn't know too much about how to improve body kenetics in a crash, just that the best way to crash is to crash slowly and in order to do that, you need a large crumple zone. A large crumple zone is still beneficial to this day regardless of star ratings. I'd say the safest car would be a Civic or even a SmartForTwo with an engine bay fit for V12 and a trunk in equal size. As for side impacts, the doors would have to be twice as wide or the passengers would be offset from the doors by a few inches, giving them more crush space.

Furthermore, I'd like to mention that a lot of trucks now have engine bays the size of cars, so when they crash, they don't have as much space to dissipate the energy over that of a car with an equally sized engine bay.

 

[Pacfanweb]

VW Bug or semi truck vs. brick wall at 100mph?

No-brainer.

The Bug is collapsed, killing the driver.

The semi truck blows through the wall, driver needs new underwear.

 

[fleabag]

Originally posted by: Pacfanweb
VW Bug or semi truck vs. brick wall at 100mph?

No-brainer.

The Bug is collapsed, killing the driver.

The semi truck blows through the wall, driver needs new underwear.

That's stupid... Just assume the wall does NOT collapse and yes that is quite easy for it to happen as the passenger cab in a semi-truck is NOT all that strong compared to say a steel reinforced concrete wall designed for major impacts.

 

[angry hampster]

Originally posted by: fleabag

Originally posted by: Pacfanweb
VW Bug or semi truck vs. brick wall at 100mph?

No-brainer.

The Bug is collapsed, killing the driver.

The semi truck blows through the wall, driver needs new underwear.

That's stupid... Just assume the wall does NOT collapse and yes that is quite easy for it to happen as the passenger cab in a semi-truck is NOT all that strong compared to say a steel reinforced concrete wall designed for major impacts.

http://www.youtube.com/watch?v=PDQ7KIF60Zs

 

[Demon-Xanth]

http://www.youtube.com/watch?v=tOs6MrYDhc4
http://www.youtube.com/watch?v=usWtTs0IdNM
http://www.youtube.com/watch?v=r_wcUFOpdjI
http://www.youtube.com/watch?v=kSg_HDFUGvI

(they were better with the original audio)

 

[Pacfanweb]

Originally posted by: angry hampster

Originally posted by: fleabag

Originally posted by: Pacfanweb
VW Bug or semi truck vs. brick wall at 100mph?

No-brainer.

The Bug is collapsed, killing the driver.

The semi truck blows through the wall, driver needs new underwear.

That's stupid... Just assume the wall does NOT collapse and yes that is quite easy for it to happen as the passenger cab in a semi-truck is NOT all that strong compared to say a steel reinforced concrete wall designed for major impacts.

http://www.youtube.com/watch?v=PDQ7KIF60Zs

Concrete wall, not brick. Big difference. Brick isn't going to hold up in an impact like that. I don't dispute the results vs. concrete, however...brick is what was mentioned initially.