Is physics class this fun

[Edubya]

AK-47 fired underwater is frighteningly beautiful


Gun fanatic or peacenik, you’ve got to admit that this video showing exactly what’s happening when you shoot an AK-47 underwater is insanely cool. Listen up as Destin fires off the weapon in a swimming pool in Alabama and proceeds to impart all sorts of higher knowledge while we soak up the ultra-slow-mo action. Put together for his SmarterEveryDay YouTube channel with help from the Slow Mo Guys, this is where you’ll learn all about the Rayleigh-Plesset equation, Bernoulli's principle and sonoluminescence. If physics class had been this much fun, we’d all have become science nerds.

http://now.msn.com/ak-47-fired-underwater-looks-beautiful-and-teaches-mechanics-of-guns

[Freightman]

Cool! no wonder they are nerds.

[Echo]

Tres Cool! Thanks for showing ...

[Edubya]

More info on "new bullet"
@: http://www.army.mil/article/56157/
EW

[williamwaco]

OK Experts.

If I calculate correctly a 16" 7.62mm barrel will contain a hair over 300 grains of water.

What would happen if you put 300 grains of mud, paper, polyester, chewing gum, ( fill in the blank here ) in that barrel, directly in front of the chamber, and fired it?

[44Vaquero]

Very neat, I was surprised how quickly the bullet tumbled!

[Bad Water Bill]

OK Experts.

If I calculate correctly a 16" 7.62mm barrel will contain a hair over 300 grains of water.

What would happen if you put 300 grains of mud, paper, polyester, chewing gum, ( fill in the blank here ) in that barrel, directly in front of the chamber, and fired it?

I have wondered about that for years.

Back to "The green Beret movie where you saw the swimmers just com[ng out of the water with water pouring out of the bbl.

Why boesn't the bbl split like a banana peal?

[Boerrancher]

Why boesn't the bbl split like a banana peal?

The reason the barrel doesn't split or the action come apart with the AK under water is because all things are equal. The amount of resistance by the water inside the barrel is equal to the amount of resistance of the water on the outside. Fluid dynamics is the same be it water or air. Only when the dynamics of the equation are thrown out of balance do we get chaos. Fill the barrel with water, fire it in the dry air and you have devastation, simply because the resistance inside the barrel is far greater than the resistance on the action.

You could do the same experiment in something as dense as mercury and the results would be the same as long as the entire weapon was submerged in the fluid. Resistance is resistance be it air, water, or oil. It just has to all be equal when added into the equation.

Best wishes

Joe

[felix]

Joe is correct. However, do NOT stick the muzzle under water and the fire as a water test, like was done in the movie with the whole gun under water. Any such "media" gradient perfects the setup for a SEE condition. Only a high tolerance revolter might make it through the ordeal but nothing else will. For sure!!! ... felix

Just remembered. My Brother, John, went quail hunting with my dad and crossed over a fence breaking all rules. He carried the shotgun with muzzle down and unknowingly picked up some snow. It was a cold day and no snow was melting. A covey was kicked up in front of pointer dogs. Both barrels came home bulged. I took the double barrel back to KC with me to Simmons in Olathe KS who at that time worked on restorations. Yes, my son has the 20 gauge now with perfect barrels. The LC Smith was purchased in 1920 for my dad. ... felix