Escape sinking car homemade tool

You can't make those go sideways. They only go up and down.

Mostly down.

This would work a lot better, particularly for a woman or kid.

This one tells you when the window is jammed against the door frame

they say it's almost impossible to get the window to roll down.

As you have calculated the pressure on any given window will depend only on the depth of the water and the area of the window glass. 1 foot = 200 pounds of pressure 2 feet = 400 pounds of pressure 3 feet = 600 pounds of pressure 4 feet = 800 pounds of pressure

Looking for where I saw that the experts said the pressure is preventing the glass from opening I can run this search just now. Here it says there's upwards of 1000 pounds holding the door closed. Here the tester said "I would have been dead" trying to open the door. Found it!

Here is a chart showing water pressure "jams" the window against the rails.

This guy says there are 400 vehicle related drownings in the USA every year.

These guys get out in an amazingly quick time. Mythbusters had a tough time getting out upside down & effectively died. Here you can see Adam's feet NOT breaking the window time & again. Paradoxically, this guy was taught to let the water get to the window half way up the window he was able to open the door surprisingly.

Yet Adam tested it such that he couldn't open the door until way later.

In fact, Adam "died" trying to open the door so that's paradoxical. This reporter doesn't know the difference between air & oxygen. Given the conflicting information, I'd trust mythbusters over that one video that says you can open the door when the water gets halfway up the window.

Reminds me of a problem from Calculus 101.... The problem that is, not the solution. I haven't used calculus in so long I doubt I could come up with a valid answer.

Calculus is good for figuring out the volume of fluid in a tank or pool.

My kids learned the essence of calculus differently than we did. Mine learned it from YouTube. Not because they wanted to. But because I made them. And YouTube was how.

You can find a million "formulaic" Calculus videos which "teach" calculus the way we learned it which was just a series of rules to the game (none of which made any sense to me but which only arrived at the correct answer).

If you add "+3Blue1Brown" to that search, you get real learning, IMHO. I recommend something like this to get back up to speed on calculus.

Thank you for noticing that wide open tailgate which I had not noticed.

It's good you told me that because it bothered me that he had such an easy time opening the door when the window was half submerged, and yet the mythbusters would have died waiting for the pressure to equalize.

In a way they're doing a disservice to people telling them to wait to that point as EVERYONE else said get that seatbelt off and break the window as soon as you can.

One video had simulated children in the back which did give the advice to get the older child out the same broken window first, as the older child could then help out a bit. Younger children last.

Oh, and don't call 911.

I've listened to EVERY car-drowning 911 call I could find on the net where it's just sad that the 911 operators used to tell people to wait for help.

Most of the people seem to think that opening the window will let more water in, which is true. What they don't seem to know is what one of the videos I saw showed which is the water comes in faster in the end than in the start.

So they get lulled into a sense of safety because the water starts seeping in slowly but as the car sinks, so does the pressure of the water wanting to come inside.

In effect that last foot of water comes in an instant while the first foot of water took some time so it's easy to miscalculate how much time you have.

I've got a copy of that for light reading. It's over 100 years old but calculus hasn't changed much :) He uses a lot of visuals like the last video, except they're ink on paper. That's my favorite medium; my mind wanders during spoken presentations. The technique reminded me of Plato's 'Meno'. You already know how to do this, you just don't remember it yet.

We used Thomas and his first edition came out in 1952 and is in the

14th edition now. I forget the author of the differential equations text.

I haven't had a use for it for many years but I've started playing around with Arduinos and things that move around in the real world so I guessing I'll get back into it sooner or later if for nothing more than implementing PID controls in software.

I used to read my father's physics books where I was amazed that in the twenties they taught math the way we currently teach high school students.

I loved them. Because I could understand them.

My college calculus and physics textbooks just gave us the equations for the most part and then we had to learn how the game worked of applying them.

But in the olden days, they didn't do it that way even in college textbooks.

It may be they didn't regularly teach calculus in high school in those days. Maybe that's why calculus started from the basics even in college textbooks.

You hit the nail on the head as to what I think is wrong with the way math is taught, both at the college level and at the high school level today.

They hand a high school kid a test comprised of twenty five quadratic equations (or whatever) that need to be solved (mechanically) to pass.

Yet not a single one of those equations was stated as a real world problem. So they are just meaningless equations to these poor high school kids. Why should they care about solving a bunch of meaningless equations? I don't blame them for not being at all interested in playing the game.

The kids who excel are either those who just care about getting good grades, or, more usefully, those who feel that the teachers must know something that the students don't know in that they'll NEED this skill in the future.

Well, I took calculus in college. I never needed it. Did you? (Of course I'm not a mechanical engineer or a rocket scientist but neither are most people. Did you ever really NEED calculus in your entire life?)

At least physics is taught as problem sets.

The high school I went to had an 'enriched curriculum' program. In the summer between my junior and senior years I took a linear equations course in preparation for calculus during my senior year. The course was in the afternoon after the normal school schedule and was taught by a professor from RPI. The high school was almost adjacent to the RPI campus so it was common to have interactions like that. The text was Thomas, which was what was used at RPI.

Calculus definitely was not part of the normal high school curriculum. The standard senior level math course was spherical trig. In retrospect, since I do a lot of GIS work, spherical trig would have been more useful. This was 1964.

After graduation, I entered RPI and had a second dose of the aptly named math professor, Dis Maly. His wife had taught the linear equations course and was great; his droning could put a hyperactive 6 year old to sleep.

Not really. The concepts are valuable but as far as sitting down with pencil and paper and solving anything no. You can know what a FFT is and even how to program the solution without delving into the notation. When I roll up my extension cord I realize that if I crank the spool at a constant rpm the speed at which the cat will need to chase the loose end increases as a function of the circumference of the wire on the spool but neither I nor the cat ever sat down and worked it out.

Physics at RPI was a two year course. We used Resnick & Halliday since Robert Resnick was a professor there. I consider that the most valuable college course I took. While I eventually migrated to software from hardware I can't say FORTRAN IV proved to be all that useful although there still is a lot of Fortran lurking around. Fortunately it has progressed past Hollerith cards. Being a lousy typist I do much better with a decent programming editor.

Brrrrrre.... RPI. Why not change the world? LOL I went to school in a warmer clime that didn't care to change the world! :) However I like that you also enjoy reading older texts such as Thomas is.

My high school taught the following, which was typical in the day I think. Freshman = Algebra 1 (required for graduation - dumbshits took it later) Sophomore = Geometry first half (required for college prep) Sophomore = Trig the second half (required for college prep) Junior = Algebra 2 (required for college prep) Senior = Calculus (recommended for college prep in the science field)

So I took all of that, but I honestly can't say I remember much of it.

I had to take Calculus again in college but only one year of it as I was in the biological sciences so we didn't need that (we took statistics though).

What I remember is the front and back of the textbook had a long list in a table of integrals, which, if memorized, was extremely important for passing the test. But, of course they were easily best forgotten soon thereafter.

About the only real takeaway was that an integral is the area under the curve and a derivative is the slope of that curve at any given point.

I've been studying the true source of gravity, which according to Minkowski and others (Marcel Grossman, Einstein, Christoffel, Ricci and more) is due to the geodesics inherent in spherical trig as I understand it anyway.

You might be able to help me as I'm trying to learn how to create geospatial PDFs for my grandchildren who are planning a week long hike into the wilderness which spans multiple USGS quadrangles.

Unlike us, they shun paper maps so I'm trying to create a specific map for them with the gpx track on the map and the map being an amalgam of geospacial PDFs so that their smartphones can show them where they are on that custom geospacial PDF.

I can tell you more about what I need if you're interested but it's kind of off topic for this newsgroup where it's more for the freeware groups since each kid is expected to download and use the maps and the map software on their Android or Apple phones.

You may have a fantastic background in better understanding the true source of gravity, which, it seems to be, is due to the curvature in 4 dimensions of what looks like straight lines to us in three dimensions, and where we're moving along those four dimensions at only one speed - the speed of light.

The only thing I learned from college about fourier transforms was that if you took any periodic signal, it would devolve down to a discrete set of sine waves. That was interesting (I remember the "Gibb's Effect" though, which threw a kink in the math - but only until final exams as I promptly forgot about that until this very moment - too many decades to care later).

I've never needed an FFT nor integrals or even derivatives other than to know the first deriviative is speed, the second is acceleration, etc.

When I need to calculate a volume, I break it down into sections of that volume. It's rare you really have the equation anyway (aka the function f(x) to do the proper math). I'm told Desmos and Geogebra will help though.

:)

Likewise, the air resistance goes up with the square of the speed, I think, which tells me the faster I go, the worse my incremental gas mileage will be.

On a note about the extension cord, what they should teach in high school is how to wrap up a hundred or two hundred footer without kinks. Yes, I know they loop it in a special way. But you have to practice it.

Seems to me we can start a thread on what _should_ be taught to kids that we old farts learned (or wish we had learned) when we were younguns.

Mine was for the bio sci majors so it was only a year of baby physics. We never got past the classical physics for example.

I took Fortran before IV existed. :) Cobol too. Yuck.

Error 45. That's all you get.

IBM JCL. Yuck.

Punched cards though. That was fancy stuff. Winchester drives too. Maybe 16KB of memory was allotted to us? Don't remember.

Heady stuff that was in the days of the raised refrigerated floors and punched cards and long feed folded printer paper printouts in the bins with your login on the first page all alphabetically sorted by the "operators."

Ah. You missed my typing class with IBM selectrics in college. Fancy stuff they were. Heavy as a boat anchor. Spinning ball and all that.

All girls. Except me.

Whooo hoo. I haven't had it that good (male to female ratio anyway) since then. Sigh.

Anyway, maybe we should start a thread on what kids _should_ be taught. Also if you can help me on my map problem for the grandkids, I'd love that.

Even with manual roll down windows, this says once the water is at the upper level of the window, it will be impossible to roll the window down.

They even said that you need to get out of the car even if you had to wait for it to equalize where if you're going to die, at least your last breath will have more oxygen in it than before, and maybe, just maybe, if you follow the bubbles & float to the surface, someone may resuscitate you.

Another college on my short list was Clarkson in Potsdam NY. My father and I drove up this time of year and the last dry pavement we saw was in Lake George. The freshman dorms were a couple of miles from the campus. I took a pass on that one. Troy was bad enough.

I took statistics. 8AM class. Boring. I haven't cared much for statistics since. The first two years were the same for everyone. After that I could mix in some more interesting stuff from the psych department. Not shrinky stuff. The department head was an old school behaviorist so it was mostly physiological, sensation and perception, and so forth. I was about 15 years early and in the wrong place for cognitive science.

That was diff e... I took it as an elective in my senior year and had better things to do than go to class. A friend who knew the TA had a bet on whether I would pass. The TA figured no way since I was seldom seen, but my friend won the bet. Intense cram session, take the final, flush it all from my brain.

I've never worked with pdf's. For display purposes we use browser based maps, mainly ESRI although I've worked with Google and Mapbox/Leaflet. They all work about the same. The basemap consists of 256x256 png tiles for the area and zoom level of interest. Once that's established You can create layers on top of the base and create graphics, either lines, polygons, or points. For a route I load a GeoJSON file and create a line graphic from the points.

The tiles are georeferenced to Web Mercator, which is essentially WGS84. You've probably found something similar to

From a quick search you can export GeoPDF from ArcMap but ESRI tools are pricey. otoh, QGIS is free.

That talks about creating a GeoPDF but doesn't go into the particulars of what he used for the basemap, probably OSM, and point/line layers. Presumably you can load GeoPDF rasters, stitch them together, create the route, and export the whole thing.

There are also GDAL/OGR tools to deal with GeoPDFs but they're not for the faint of heart.

You might poke around

QGIS isn't super intuitive but neither is ArcDesktop or ArcGIS Pro. The difference is about $5000.

And power is proportional to the cube of velocity... Misbegotten youth messing around with cars. The interstate speed limit in this state is

80 and the Toyota gets thirsty at that speed. The bikes aren't much better. Less frontal area but they have a drag coefficient like a barn door.

The fourth semester was quantuum physics where it started to get weird.

I've managed to miss Cobol completely. Fortran was viewed as an engineering tool similar to a slide rule or analog computer. I don't think they really saw programming as a career path. A couple of my friends who were the nerds with the op code cheat sheet in their shirt pockets dropped out and got real jobs.

RPI had ties to IBM so they got a System 360/30 hot off the assembly line:

16KB sounds about right. For matrix operations you had to write partial products to tape, rewind, take another pass, rinse and repeat. I thought it sucked. I really didn't get interested until about 10 years later when microprocessors started replacing relay or TTL logic in industrial systems.

Ah, the god-like operators... When I was there the computer was in s nondescript new brick building but then they did it right:

*1200xx3372-1897-0-143.jpg They'd bought St. Joseph's Seminary property in '58 and that was the chapel. It was the library when I was there but they tore down the main building and built a new library on the site. Now you can go in and light a candle to St. Leibowitz.

In high school the business and shop kids tool Spanish and Typing. The college entrance type took Latin and some other stuff. Spanish and typing would have been much more useful to me.

My brother who was somewhat older and I and the rocket scientist in the family wouldn't know what to do with a typewriter if he fell over it. In his day engineers had secretaries to handle that sort of thing.

Critical thinking would be a good start but that would require a change of direction and the realization that many kids aren't equipped to handle it.

I very briefly taught math and science in junior high. The system used homogeneous grouping for the classes, A through D, with D standing for dumb. The same syllabus was used regardless. The A kids could grasp the sexagesimal Babylonian number system, more or less. The D kids were seriously in need of learning the decimal system so they could make change at Mickey D's.

From what I understand today the syllabus is designed for the D level.

The door lock won't matter if we can't open the door (which by almost all accounts, can't happen except in the first few seconds which the mythbusters tested (Adam almost got his leg crushed by the door when he did it though).

And the rolldown windows won't matter if the videos are correct that there are hundreds of pounds of sidewise pressure pushing the window against the door jamb once the water level rises enough.

That's why it's important to teach our wives, children, and grandchildren that they don't have any choice but to get out of that car immediately. a. If they can open the door, do it (but they likely can't) b. If they can open the window, do it (but they likely can't) c. They most likely have to break the window to get out

I've listened to every car drowning 911 on the Internet where they seem to feel "safe" inside the car, and they begin to get scared when the water level on the window is higher than it is inside the car.

They feel that opening the window will "let the water in", which is why they feel safer inside the car.

In this tunnel death, I suspect they simply felt safer inside the car.

What perhaps they didn't know was that the water fills up faster as the car sinks lower - or maybe they figured the pavement was closer than it was.

For example, if the pavement was only 3 feet below the water level, they would have settled to the roadway with enough of an air pocket to survive.

This exact point in that exact video must have been the couple's nightmare.

That car I think didn't have a working electrical system where it would be interesting to figure out how long it takes for the system to short out.

Even so, when I saw the (much longer) original video, I think it still took Adam another 10 or so seconds after the car settled to the bottom before the pressure equalized enough to open the door, which is 10 (or so) very critical sections to be holding your breath.

I wonder what this couple "thought" when they went into the water? What scenario do you envision actually happened (since we know it's real)?

[snip]

I remember my first trig class, which wasn't very useful. The teacher spent the whole period going around and helping students to find the right buttons on their calculators. Nothing was said about what trig IS.

[snip]

Calculators?

Calculators?

I bet they would have cost thousands of dollars in my day. :) And taken up the entire classroom and electrical supply too.

Eventually by the end of my trig semester we knew every value by heart. Just as we did with hex when we learned to program in assembly language.

I forgot it all though. Long ago.

I wonder if it ever comes back?

.7071. That does double duty as a sine and cosine. 0.0000 and 1.0000 are also useful. As for the rest

#include <stdlib.h>

#include <stdio.h>

#include <math.h>

#define PI 3.1415926

int main(int argc, char** argv) { double degrees;

degrees = atof(argv[1]); printf("the sine of %f degrees is %f\n", degrees, degrees * PI/180.0); return 0; }

~ $gcc sin.c -lm -o sin ~ $./sin 45 the sine of 45.000000 degrees is 0.707107

When all you have is a hammer...