[snarfybarfy]

While I agree with your general point, I have to take objection to your car analogy.

Whether a car is travelling at 30 or 40mph makes a huge difference.

Kinetic energy is the square of the velocity and it also affects reaction time:

Total stopping distance (reaction time + braking distance):

@30mph = 44 feet + 43 feet = 87 feet

@40mph = 59 feet + 76 feet = 135 feet

Which means that chances are fairly good if you hit something 60 feet away going 30mph, but pretty grim going 40mph (basically full speed impact).

http://www.forensicdynamics.com/stopping-braking-distance-ca...

[dsfyu404ed]

This is wrong. Kinetic energy is not what kills you. Force is not what kills you (the human body can handle triple digit G forces for a short time). Hitting things in the cabin is what kills you. The only way kinetic energy is related is that it also happens to increase with speed.

Using kinetic energy to imply that lethality goes up exponentially with speed is misleading at best.

[snarfybarfy]

Are you by any chance one of those people that still believe seat belts are for sissies?

Because you can just hold tight to the steering wheel?

And yes the kinetic energy per se does not kill you. It's when the kinetic energy gets converted to elastic/inelastic transformation of your head that you die. There is a clear correlation of speed and survivability.

See: http://www.humantransport.org/sidewalks/SpeedKills.htm

5% chance of dying @ 20mph

85% chance of dying @ 40mph

[dsfyu404ed]

>And yes the kinetic energy per se does not kill you. It's when the kinetic energy gets converted to elastic/inelastic transformation of your head that you die. There is a clear correlation of speed and survivability.

Kinetic energy does nothing. NOTHING!

It's all about acceleration (which is roughly interchangeable with force since the mass of the person is constant). The human body can deal with triple digit G forces for a short time (on the order of how long a car crash takes) so long as it's mostly in the forward direction and you have a good harness. They figured this out decades ago when designing escape systems for fighter jets (no point ejecting at Mach 1 if you're gonna get killed when you hit the outside air at that speed).

Of course speed kills when you're talking about hitting pedestrians. When you have several thousand pounds of mass vs a couple hundred the acceleration (and therefore force, because mass is fixes) on the few hundred will depend almost wholly on the speed of the several thousand pounds of mass. It still has exactly nothing to do with kinetic energy. For limited access highways, rural roads and other places pedestrians are not a meaningful concern this is irrelevant.

>Are you by any chance one of those people that still believe seat belts are for sissies?

The people who use straw-men of this caliber in online arguments is a subset of people who should avoid seatbelts if you catch my drift.

[snarfybarfy]

There is the same correlation in regards to vehicle occupants. At some point the kinetic energy becomes so great that the body of the car is unable to absorb it sufficently and then the remaining energy kills you.

No straw men anywhere in my line of argument. Just a cheap dig. Sorry for that.