From an article in yesterday's Boston Globe about Toyota's plans to resolve some safety (and PR) issues:
[...] There have been about 200 complaints in Japan and the U.S. about a delay when the brakes in the Prius were pressed in cold conditions and on some bumpy roads. The delay doesn't indicate a brake failure. The company says the problem can be fixed in 40 minutes with new software that oversees the controls of the antilock brakes [...] U.S. safety officials are investigating the brake problem. It is suspected in four crashes [...]
I'm not sure why it would not be called a brake failure. A car crashes into something because the brakes don't function properly.
I am reminded of Mr. Puffett, the character in Dorothy L Sayers's Busman's Honeymoon who is employed to get the fireplace working. Every time anyone uses the word "chimney" in mentioning the problem, he gets defensive, saying that there's nothing wrong with this here chimney, the problem is the soot, or words to that effect.
A Salt Hygrometer
19 hours ago
14 comments:
Right. Not fair to a man, NOR his rods. Or words to that effect. But he was RIGHT - allowing for the height & pitch of the gable. While I doubt Toyota is.
I hope that Toyota is right about something, because my Camry was subject to their gas pedal quick-fix recall.
I get 240,000 ghits for "brake failure" and 95,000 for Toyota "brake failure", so whether they like it or not a lot of people connect the two. They'd probably prefer us to call it a parts-supplier failure.
I did like the Prius when I sat in one, but it doesn't have a towing hook. Bourgeois? Me?
I didn't like the Prius when I sat in one, simply because of a shortage of head room. So I bought a Camry instead -- also hybrid but not as fuel-efficient.
Hmm, Camry looks really good. But we need a stationwagon with a towing hook. Although I wouldn't mind one of those Tesla electric sports cars.
I get 40,100 hits for "break failure". Apparently it has adverse effects on spelling as well as driving. Here's one:
My mother just got into an accident going across a major 4 lane road because the breaks on the Camry hybrid failed to break.
By the way, the statement "The delay doesn't indicate a brake failure" was not presented as a quote from somebody at Toyota. It looked like a statement of fact by the newspaper reporter.
Oh, give me a brake! I expect "brake failure" has some technical meaning that has nothing to do with brake failure, sort of like the definitions in physics that I'm having to relearn with my daughter: work, etc. By the way, in our quest for a good grade in physics we are currently enjoying the short lectures on Newton's laws & so on given by Julius Sumner Miller. They can be seen via Youtube. I gather he was popular on tv in the US & Australia when we were young. He has that excited urgency in his delivery that good teachers often have, combined with a loony quality that works well on telly.
I'm just now watching his "Bernoulli 1" presentation. What great stuff for kids !!! And for me too. I didn't know that the pressure drops, and the velocity increases, when air flows through a constriction in a pipe. That's the Venturi effect. Apparently Bernoulli provided a mathematical explanation for it. I would have thought the pressure rises, and the velocity decreases - sort of like constipation.
What did I learn about the world from those courses in electromagnetism and relativistic wave mechanics that I took ? Zilch.
Now I know how to crush those empty milk boxes, without using my hands. I could just direct a stream of air across the top opening - through a narrow pipe with an opening downwards into the milk box. Miller just did that with empty tin canisters. To think that that is the result of ambient air pressure !
I'm going to become a mad scientist, you just watch.
With an incompressible fluid, constipation sets in only at a velocity of Mach 1. That is called "obstructed flow".
I seem to have been taught to call this Venturi effect the Bernoulli effect. It is invariably said that it is the key to making airplanes fly: the shape of the wing is designed to produce more pressure below than above when the thing moves forward. But I am ashamed to say that I have never looked into the mathematics behind it.
The macro math is simple: the pressure drop at the constriction is 1/2 the difference of the squares of the velocities (v1 before the constriction, v2 in it). The WiPe article on the Bernoulli principle is surprisingly detailed.
But Miller's lecture tells you more neat stuff.
It wasn't the height of the gable or the angle that was unfair to Mr Puffett and his rods, it was the "corroded sut" which was in fact soot compacted and hardened over many years because the chimney was never cleaned. The vicar solved the problem by firing a shotgun up the chimney, which as well as the sut brought down many things, including an item which was a vital clue to finding the murderer.
By chance, I finished re-reading Busman's Honeymoon yesterday ...
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