Underwater Car

Ok... You tell us all the time about your expertise and experience in such stuff and how we at home should not try this. Well, this episode was going so well and the first I've seen in a while I had nothing to comment about other then how I was enjoying it and how scientific it appeared.

And then... you went on to experiment with the window-crushing tools, and the second i saw it, I was horrified! But still you went on to test the theory! LUCKILY, you were doing this in a pool and decided that you didn't want to leave shattered glass behind for the students - dangerous right? - and went with a substituting high-voltage elevator solution.

Well, did you ever concider the force that those pieces of glass will be flying back at anyone that attempted this mythbuster solution and crushed their door-window, possibly (ironically) fataly wounding themselves.

Please don't test the probability of death while attempting to flee a sinking car through a crushed window (dangerous all by itself) after shattering it against high pressure on the other side. just discourage people from doing this.

This method seems very "last option". I mean, if you are quick to react, just open the door - no point in crushing the window. Otherwise, crush the window too soon, you might get hurt really bad - I'm just recalling the scene where the water RUSHED into the car at a high pace after the high-voltage elevator snapped open the window. If you wait too long - you are dead or you are able to open the door.

My addition to the solutions is, open rear door window(s) (easier if they are electrically controlled). Water will fill up and pressure equalize more quickly. Hey, you might even be able to escape through there sooner if half of the car is already submerged before you start wondering how you got there in the first place!

anyhoo, that's my part... good luck!

fqa

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Adam piled 350 lbs on the window; this is a gross miscalculation of the pressure difference across the window.. The pressure on the window related to water pressure obviously varies by depth, therefore the total pressure difference across the window due to water must be calculated by using integral calculus, integrating the 'pressure v. depth' function, over the height of the window. Assuming a window which is 24 by 24 inches, the extra pressure on the window is only about 30 lbs, not 350, when the water level is at the top of the window.
Furthermore, the setup arranged by Adam requires the window motor to overcome 350 lbs of inertia, which would not be present in the actual underwater situation.
Finally, frictional forces underwater would be less than in the dry scenario.
As far as I could see, the option of cranking down the window manually or electrically while in the emergency situation was not shown, except with "high voltage" and "lubricant." Would normal window opening work? From what was shown on the show, we don't know whether that was tested, and what the result might have been.

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