The Physics of Rollovers
Rollovers kill about 10,000 people a year in the US. This is a slightly accelerating trend due to the popularity of SUVs. Understanding how rollovers occur can help in prevention, and it can also help in understanding why manufacturers can help reduce rollover accidents with SUVs and other automobiles.
I often try to explain the nuts and bolts of the physics involved, but I'm no physicist. Here's a good article on the topic. Right up front the problem is spelled out in plain english:
I won't bore you with the play by play of the long(ish) article on the physics of rollovers, but I will say that you should read the whole thing, while I point out some interesting tidbits... such as this nugget:
I often try to explain the nuts and bolts of the physics involved, but I'm no physicist. Here's a good article on the topic. Right up front the problem is spelled out in plain english:
The reasons why SUV rollover accidents happen so often are simple High School Physics. With a high center-of-gravity and a comparatively narrow track, such vehicles are relatively unstable as a natural fact. Unless either the track is greatly widened or the center-of-gravity lowered, the situation cannot be improved.In other words, even your grandma knows why SUVs flip, cause they're too tall and narrow. I call them "skin and bone"... mainly cause no one wants to admit they're riding around in nothing but "skin and bone" but also because its the truth. If they made SUVs a little fatter (as in a Humvee) or a little shorter (as in a station wagon) the problem would simply not occur as often. But that's not physics, thats just common sense as Mark Twain might say.
I won't bore you with the play by play of the long(ish) article on the physics of rollovers, but I will say that you should read the whole thing, while I point out some interesting tidbits... such as this nugget:
That's right. Our good friends "the tires" don't just make sure our ride is smooth, they make sure we're riding on the ground and not flying through the air. Thats why you don't usually see a product liability action against an auto manufacturer involving a rollover without the tire company as a named defendant. Anyway, just wanted to point that out... tires, and tire selection, are a huge part of the rollover epidemic. Also of note:In physics, a force can be thought of as a "resultant force" which is a combination of two "component forces."
We know that the tire treads are going to somehow be involved, especially since we know that on icy roads, the vehicle does not turn. So we know that the sideways force must be being applied between the tire treads and the roadway.
The center of gravity is always above the ground. For a fairly tall vehicle like an SUV, it can commonly be 30" (or more) above the ground. Vehicle manufacturers used to divulge the height of the center-of-gravity of their vehicles, but they no longer do.Emphasis added with a final "gee, don't you wonder why?" at the end!
