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April 15, 2009 at 3:33 PM in reply to: OT: Big Car Versus Small Car: IIHS confirms the law of physics. #381534
SDEngineer
Participant[quote=sdduuuude]
Such as trees, ditches, fences, walls, houses, sign-posts ? Maybe we should make all these smaller, too.
By the way, when FLU cites “Physics,” he means this:
For the same rate of decelleration, the cars may perform the same. The problem is, when a 1000 lb car hits a tree it decellerates much faster than when a 3,000 lb vehicle hits a tree, and it is decelleration that hurts you.
It really is simple physics. The weight of the vehicle doesn’t necessarily protect you because it is stronger or built better. They are simply heavier and carry more inertia or potential energy. You simply can’t design around this.
They say falling doesn’t kill you, its the sudden stop at the end. Such is a traffic accident. In a heavier vehicle, the stop is simply less sudden than in a lighter vehicle.
[/quote]
Both vehicles decelerate at the same rate (or at least close enough to make no difference, assuming crumple zones and such are somewhat larger on a larger vehicle) when they hit a stationary object.
The only case where this isn’t true is where the stationary object is light enough to be destroyed or moved by the heavier vehicle and not by the smaller vehicle.
Mass only comes into the potential energy of the collision assuming an impact with a stationary object. The large car NEEDS larger crumple zones and such because it has much more potential energy to be absorbed than the small car.
p = mv.
April 15, 2009 at 3:33 PM in reply to: OT: Big Car Versus Small Car: IIHS confirms the law of physics. #381805SDEngineer
Participant[quote=sdduuuude]
Such as trees, ditches, fences, walls, houses, sign-posts ? Maybe we should make all these smaller, too.
By the way, when FLU cites “Physics,” he means this:
For the same rate of decelleration, the cars may perform the same. The problem is, when a 1000 lb car hits a tree it decellerates much faster than when a 3,000 lb vehicle hits a tree, and it is decelleration that hurts you.
It really is simple physics. The weight of the vehicle doesn’t necessarily protect you because it is stronger or built better. They are simply heavier and carry more inertia or potential energy. You simply can’t design around this.
They say falling doesn’t kill you, its the sudden stop at the end. Such is a traffic accident. In a heavier vehicle, the stop is simply less sudden than in a lighter vehicle.
[/quote]
Both vehicles decelerate at the same rate (or at least close enough to make no difference, assuming crumple zones and such are somewhat larger on a larger vehicle) when they hit a stationary object.
The only case where this isn’t true is where the stationary object is light enough to be destroyed or moved by the heavier vehicle and not by the smaller vehicle.
Mass only comes into the potential energy of the collision assuming an impact with a stationary object. The large car NEEDS larger crumple zones and such because it has much more potential energy to be absorbed than the small car.
p = mv.
April 15, 2009 at 3:33 PM in reply to: OT: Big Car Versus Small Car: IIHS confirms the law of physics. #381996SDEngineer
Participant[quote=sdduuuude]
Such as trees, ditches, fences, walls, houses, sign-posts ? Maybe we should make all these smaller, too.
By the way, when FLU cites “Physics,” he means this:
For the same rate of decelleration, the cars may perform the same. The problem is, when a 1000 lb car hits a tree it decellerates much faster than when a 3,000 lb vehicle hits a tree, and it is decelleration that hurts you.
It really is simple physics. The weight of the vehicle doesn’t necessarily protect you because it is stronger or built better. They are simply heavier and carry more inertia or potential energy. You simply can’t design around this.
They say falling doesn’t kill you, its the sudden stop at the end. Such is a traffic accident. In a heavier vehicle, the stop is simply less sudden than in a lighter vehicle.
[/quote]
Both vehicles decelerate at the same rate (or at least close enough to make no difference, assuming crumple zones and such are somewhat larger on a larger vehicle) when they hit a stationary object.
The only case where this isn’t true is where the stationary object is light enough to be destroyed or moved by the heavier vehicle and not by the smaller vehicle.
Mass only comes into the potential energy of the collision assuming an impact with a stationary object. The large car NEEDS larger crumple zones and such because it has much more potential energy to be absorbed than the small car.
p = mv.
April 15, 2009 at 3:33 PM in reply to: OT: Big Car Versus Small Car: IIHS confirms the law of physics. #382042SDEngineer
Participant[quote=sdduuuude]
Such as trees, ditches, fences, walls, houses, sign-posts ? Maybe we should make all these smaller, too.
By the way, when FLU cites “Physics,” he means this:
For the same rate of decelleration, the cars may perform the same. The problem is, when a 1000 lb car hits a tree it decellerates much faster than when a 3,000 lb vehicle hits a tree, and it is decelleration that hurts you.
It really is simple physics. The weight of the vehicle doesn’t necessarily protect you because it is stronger or built better. They are simply heavier and carry more inertia or potential energy. You simply can’t design around this.
They say falling doesn’t kill you, its the sudden stop at the end. Such is a traffic accident. In a heavier vehicle, the stop is simply less sudden than in a lighter vehicle.
[/quote]
Both vehicles decelerate at the same rate (or at least close enough to make no difference, assuming crumple zones and such are somewhat larger on a larger vehicle) when they hit a stationary object.
The only case where this isn’t true is where the stationary object is light enough to be destroyed or moved by the heavier vehicle and not by the smaller vehicle.
Mass only comes into the potential energy of the collision assuming an impact with a stationary object. The large car NEEDS larger crumple zones and such because it has much more potential energy to be absorbed than the small car.
p = mv.
April 15, 2009 at 3:33 PM in reply to: OT: Big Car Versus Small Car: IIHS confirms the law of physics. #382173SDEngineer
Participant[quote=sdduuuude]
Such as trees, ditches, fences, walls, houses, sign-posts ? Maybe we should make all these smaller, too.
By the way, when FLU cites “Physics,” he means this:
For the same rate of decelleration, the cars may perform the same. The problem is, when a 1000 lb car hits a tree it decellerates much faster than when a 3,000 lb vehicle hits a tree, and it is decelleration that hurts you.
It really is simple physics. The weight of the vehicle doesn’t necessarily protect you because it is stronger or built better. They are simply heavier and carry more inertia or potential energy. You simply can’t design around this.
They say falling doesn’t kill you, its the sudden stop at the end. Such is a traffic accident. In a heavier vehicle, the stop is simply less sudden than in a lighter vehicle.
[/quote]
Both vehicles decelerate at the same rate (or at least close enough to make no difference, assuming crumple zones and such are somewhat larger on a larger vehicle) when they hit a stationary object.
The only case where this isn’t true is where the stationary object is light enough to be destroyed or moved by the heavier vehicle and not by the smaller vehicle.
Mass only comes into the potential energy of the collision assuming an impact with a stationary object. The large car NEEDS larger crumple zones and such because it has much more potential energy to be absorbed than the small car.
p = mv.
April 14, 2009 at 10:15 AM in reply to: OT: Big Car Versus Small Car: IIHS confirms the law of physics. #380639SDEngineer
Participant[quote=flu]
Not exactly. Read the other part of about mini cars crashing into stationary objects. Smaller car => less energy absorption.
heh heh
[/quote]Not exactly x2. p=mv. A smaller car, being lighter, has much less momentum than a larger, heavier car, which means the collision energy with a stationary object is much lower, hence, they don’t need to absorb as much energy to provide driver protection in a collision. It doesn’t completely offset, but it’s not as cut and dried as you make it seem here.
It’s when you get into collisions with two moving objects that relative mass really puts the small car at a disadvantage.
April 14, 2009 at 10:15 AM in reply to: OT: Big Car Versus Small Car: IIHS confirms the law of physics. #380912SDEngineer
Participant[quote=flu]
Not exactly. Read the other part of about mini cars crashing into stationary objects. Smaller car => less energy absorption.
heh heh
[/quote]Not exactly x2. p=mv. A smaller car, being lighter, has much less momentum than a larger, heavier car, which means the collision energy with a stationary object is much lower, hence, they don’t need to absorb as much energy to provide driver protection in a collision. It doesn’t completely offset, but it’s not as cut and dried as you make it seem here.
It’s when you get into collisions with two moving objects that relative mass really puts the small car at a disadvantage.
April 14, 2009 at 10:15 AM in reply to: OT: Big Car Versus Small Car: IIHS confirms the law of physics. #381100SDEngineer
Participant[quote=flu]
Not exactly. Read the other part of about mini cars crashing into stationary objects. Smaller car => less energy absorption.
heh heh
[/quote]Not exactly x2. p=mv. A smaller car, being lighter, has much less momentum than a larger, heavier car, which means the collision energy with a stationary object is much lower, hence, they don’t need to absorb as much energy to provide driver protection in a collision. It doesn’t completely offset, but it’s not as cut and dried as you make it seem here.
It’s when you get into collisions with two moving objects that relative mass really puts the small car at a disadvantage.
April 14, 2009 at 10:15 AM in reply to: OT: Big Car Versus Small Car: IIHS confirms the law of physics. #381148SDEngineer
Participant[quote=flu]
Not exactly. Read the other part of about mini cars crashing into stationary objects. Smaller car => less energy absorption.
heh heh
[/quote]Not exactly x2. p=mv. A smaller car, being lighter, has much less momentum than a larger, heavier car, which means the collision energy with a stationary object is much lower, hence, they don’t need to absorb as much energy to provide driver protection in a collision. It doesn’t completely offset, but it’s not as cut and dried as you make it seem here.
It’s when you get into collisions with two moving objects that relative mass really puts the small car at a disadvantage.
April 14, 2009 at 10:15 AM in reply to: OT: Big Car Versus Small Car: IIHS confirms the law of physics. #381275SDEngineer
Participant[quote=flu]
Not exactly. Read the other part of about mini cars crashing into stationary objects. Smaller car => less energy absorption.
heh heh
[/quote]Not exactly x2. p=mv. A smaller car, being lighter, has much less momentum than a larger, heavier car, which means the collision energy with a stationary object is much lower, hence, they don’t need to absorb as much energy to provide driver protection in a collision. It doesn’t completely offset, but it’s not as cut and dried as you make it seem here.
It’s when you get into collisions with two moving objects that relative mass really puts the small car at a disadvantage.
SDEngineer
Participant[quote=Unixed]$1800, wow! If you do not mind me asking, where did you go? I just got a quote from JCPenney for $2,500 plus tax. I am still shopping around, but it seems as if you received a great deal.
We are still trying to figure out what to do with our sliding door. I am voting for drapes, but my wife still has to pick out the colors.[/quote]
Wood stained are more expensive than white blinds, as is true wood versus faux wood. I priced out blinds at Home Depot, just the basic white faux wood and they came out to about 2K for the whole plan 6. It also depends on the number of windows – the plan 6 has a LOT of windows – more, I think, than the plan 2 that PKMAN has.
SDEngineer
Participant[quote=Unixed]$1800, wow! If you do not mind me asking, where did you go? I just got a quote from JCPenney for $2,500 plus tax. I am still shopping around, but it seems as if you received a great deal.
We are still trying to figure out what to do with our sliding door. I am voting for drapes, but my wife still has to pick out the colors.[/quote]
Wood stained are more expensive than white blinds, as is true wood versus faux wood. I priced out blinds at Home Depot, just the basic white faux wood and they came out to about 2K for the whole plan 6. It also depends on the number of windows – the plan 6 has a LOT of windows – more, I think, than the plan 2 that PKMAN has.
SDEngineer
Participant[quote=Unixed]$1800, wow! If you do not mind me asking, where did you go? I just got a quote from JCPenney for $2,500 plus tax. I am still shopping around, but it seems as if you received a great deal.
We are still trying to figure out what to do with our sliding door. I am voting for drapes, but my wife still has to pick out the colors.[/quote]
Wood stained are more expensive than white blinds, as is true wood versus faux wood. I priced out blinds at Home Depot, just the basic white faux wood and they came out to about 2K for the whole plan 6. It also depends on the number of windows – the plan 6 has a LOT of windows – more, I think, than the plan 2 that PKMAN has.
SDEngineer
Participant[quote=Unixed]$1800, wow! If you do not mind me asking, where did you go? I just got a quote from JCPenney for $2,500 plus tax. I am still shopping around, but it seems as if you received a great deal.
We are still trying to figure out what to do with our sliding door. I am voting for drapes, but my wife still has to pick out the colors.[/quote]
Wood stained are more expensive than white blinds, as is true wood versus faux wood. I priced out blinds at Home Depot, just the basic white faux wood and they came out to about 2K for the whole plan 6. It also depends on the number of windows – the plan 6 has a LOT of windows – more, I think, than the plan 2 that PKMAN has.
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