The MythBusters The MythBusters

MythBusters Episode 72: Underwater Car

Premier Date: January 24, 2007

If a car falls into the water and becomes submerged, you cannot open the door until the interior is flooded.

confirmed

The pressure differential between outside and inside when the car is submerged is too great for a man to force the door, and the pressure must first be equalized, which means the interior must be flooded first. But it should be noted that Adam was forced to resort to emergency air in his first test. A second test later showed it to be possible to escape the car simply by opening the door, but only by remaining calm and not attempting to open the door until the interior is well and truly flooded, so as to conserve oxygen while holding your breath.

You can escape a car that has fallen into the water immediately after hitting the water.

confirmed

There is not enough water pressing on the door to keep it shut. Adam escapes easily.

You can escape a car that has fallen into the water as soon as the water inside the car is up to your waist.

confirmed

Adam barely manages to force the door open and is even briefly submerged before he emerges from the car.

You can escape a car that has fallen into the water as soon as water covers the car window from the outside.

busted

At this point, the pressure differential has become too great. Adam is unable to escape.

You can open a window in a submerged car by using a manual window crank.

busted

Using a test weight of 350 lbs (equivalent to pressure differential from just two feet of immersion), the pressure of the window glass against the frame is so great that no amount of effort can move the gear. You are more likely to break the window handle.

You can open a window in a submerged car by opening power windows.

busted

Though more powerful, power windows still cannot overcome the pressure differential. Contrary to popular belief, though, power windows can withstand immersion in fresh water for prolonged periods and still function.

You can open a window in a submerged car by attempting to break the window using a set of keys.

busted

Window glass is tempered and resistant to impact from blunt objects. Keys are ineffective.

You can open a window in a submerged car by attempting to break the window using a cell phone.

busted

A cell phone is ineffective.

You can open a window in a submerged car by attempting to break the window using steel-toed boots.

busted

Boots are ineffective.

You can open a window in a submerged car by attempting to break the window using a window-breaking hammer.

confirmed

The device is designed with a pointed tip designed to shatter tempered glass. The hammer breaks the window on the first try.

You can open a window in a submerged car by attempting to break the window using a spring-loaded center punch.

confirmed

The point of the punch can work like the tip of the hammer, and punches are sold for the purpose of breaking window glass. The punch breaks the window on the first try.

A piece of paper cannot be folded in perpendicular halves more than seven times, regardless of its size.

busted

It was impossible to fold a piece of letter-sized (8.5" x 11", 216 mm x 279 mm) 20 lb (37 g/m2) copy paper with perpendicular folds more than seven times. The thickness of the paper exponentially grew with each successive fold, and after the seventh fold the paper was just too thick to fold without breaking. The MythBusters then laid out a football field-sized sheet of interconnected paper (170 ft x 220 ft, 51.8 m x 67.1 m), and due to the reduction of its thickness-to-area ratio, were able to perpendicularly fold the paper 11 times.