Thanksgiving turkey 2

[SAIL3]

The thanksgiving holiday is fast approaching and in that spirit, here is a problem to ponder over the holidays.
A submarine is submerged and stationary 500ft below the surface of the ocean.
In a cabin right next to the chow hall, a 100lb turkey was resting on a table when it happened to overhear two cooks discussing plans for the upcoming thanksgiving dinner.
What it heard threw it into a panic and it flew into the air and began to fly around the cabin in great distress.

Question: has the equilibrium/buoyancy of the submarine changed?

 

[drawoh]

SAIL3,

Unless the turkey's mass somehow exits the sub, there should be no change to buoyancy due to the turkey.

With a 100lb turkey rampaging around the sub, there may be a change in buoyancy due to sailors using the escape hatch.

JHG

 

[hawkaz]

Mass can't be destroyed- just converted to a different form (unless the turkey flies into the nuclear reactor- then it could be converted to energy). Since this is a closed system, the extra 50 lbs the bird lost needs to go somewhere.

No effect on buoyancy due to this factor alone.

 

[IRstuff]

Buoyancy can be thought of as the effective density of the object relative to the water displaced. The physical volume of the sub does not change, and variance in apparent weight is rather miniscule.

A brute force estimate would be 100lb*500ft/(7800ton+100lb) = 0.98mm.

In a real ocean with real currents and waves, that's prit near undetectable.

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[racookpe1978]

Why the 500 foot lever arm?

 

[IRstuff]

Not lever arm, depth. I was trying to brute force the change in neutral buoyancy depth.

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[IDS]

I think we should simplify things and look at the turkey on the International Space Station first.

In this case there is no change in the external forces on the ISS, so whatever the turkey does has exactly zero effect on the position of the centre of mass of the ISS (including the turkey and the air). Any movements of the turkey are balanced by equal and opposite changes in air density, and small changes in the position of the structure of the station.

Back in the submarine, if we assume (for simplicity) that the turkey takes off entirely by interaction of its wings with the air, as it takes off there will be a balancing compression wave in the air. For a short period the centre of mass of the submarine (including turkey and air) will remain exactly on it's previous course, but when the compression wave hits the surface of the submarine there will be some small interaction between the surface and the water, and there will be a small change in the external force on the submarine, and hence an accelleration. This will be balanced by a compression wave going off through the ocean, and eventually through the Earth, so there will not be any change in the path followed by the planet, no matter how carefully we measure it.

All these changes (other than the change of air pressure under the turkey's wings) are much too small to measure in practice.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[Andries]

A 100 lb turkey must be an ostrich.

Andries

 

[CRG]

If the turkey jumps up and down in the roasting pan in the kitchen of the sub, the instantaneous buoyancy of the sub changes. If I jump up and down on the bathroom scale, the instantaneous reading will change; however, the average will remain the same less the lost efficiency of a fat guy sweating and loosing heat.

 

[MiketheEngineer]

T-day is in a couple of days - send me that 100 lb turkey and I will cook it, eat it and put an end to this mess....

 

[Duwe6]

the Real equation:

100# muscular turkey onboard SSN / SSBN + [2ea. to 20ea. farmboys] + probability of 0.08 of Cajun in crew =

5 to 18 lb segments of marinated turkey run thru deep-fat fryers until golden brown and ready to eat. NOTE: weight gain due to injection of marinade will be offset to within 18.73% due to the water loss inherent in deep-fat frying All water converted form liquid to vapor will be deeply inhaled by hungry crewmen, thus maintaining a balanced water quantity, with only phase change losses generating more heat and chaotic conditions.

THUS: the net equibrilibrum of said submarine will remain balanced until such time as the Sanitary Waste Dispisal NCO blows out the contents of the Sanitary Holding Tank.

Q.E.D.

 

[SAIL3]

ok here is my take on it....
turkey resting on the table....gravity forces resisted by buoyancy
forces equals equilibrium.

turkey starts to fly....energy of turkey is resisting gravity
force of turkey...submarine rises
accordingly to reflect the 100lb change..
This implies that the weight of the turkey
is being resisted by the energy expended
by the turkey and not by a buoyant force,
otherwise, one would be doubling the
resisting force..


turkey losing weight...the energy expended by the turkey to defy
the force of gravity..

turkey lands back on table....50lbs lighter..submarine sinks to
account for the now static 50lb
bird.

total change in buoyancy is 50lbs ..the 50lbs lost was expended
energy, say heat generated,etc...
This seems to defy logic and may be incoherent but I'm sticking to it until proven otherwise,which may not take long...

 

[mijowe]

"as god as my witness, I thought turkeys could fly"

http://www.youtube.com/watch?v=ST01bZJPuE0&feature=related

 

[paddingtongreen]

Imagine for a moment, a turkey riding on a flatbed truck. As the truck rolls along the turkey causes a constant force, then it decides to jump, it flexes it's knees, reducing the force until suddenly increasing it to gain escape velocity by straightening it's legs.

Does it's head cut through the air above or does it raise a column of the air? I don't know, do you?

Apply to the wings pushing up and down and similar questions must be answered first.

Michael.
Timing has a lot to do with the outcome of a rain dance.

 

[IRstuff]

Orbital examples are not the same problem, because orbital objects are in freefall, and aside from microgravitational aspects, are completely superimposable.

Turkeys are not rockets, so they cannot move without pushing against something, be it air or the floor.

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[IDS]

>>

Orbital examples are not the same problem, because orbital objects are in freefall, and aside from microgravitational aspects, are completely superimposable.Turkeys are not rockets, so they cannot move without pushing against something, be it air or the floor.

<<

But turkeys are not rockets when they are inside a space station either.

The submarine example is not the same as the orbital one because the submarine interacts with the water, but in the brief time while the air compression wave travels from the turkey wing to the surface of the sub, they are the same.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[SAIL3]

as the turkey flies around it flaps it's wings then glides for awhile, then flaps it's wings again...

during the wing flapping....ok there may be a compression wave
generated, but this an internal
pressure wave and does not change
the buoyancy of the sub.
Now, however, an external pressure
wave on the sub would cause it to
momentarily change the buoyancy.

during the gliding....to generate lift on the wing the air
pressure underneath the wing can remain the
same as surrounding air but the air press
over top of wing is less than surrounding
air, thus generating lift. This is a local
condition and does not generate a
compression wave. At least, this how I see
at the moment..

 

[MiketheEngineer]

It time to "cook" this bird!!

 

[IDS]

Sail3 - it's mu understanding that gliding involves a pressure increase under the wing, as well as a pressure reduction over the wing, but it doesn't matter for this discussion. It is these pressure differences that are holding the turkey up, and when the pressure waves hit the surface of the submarine there will be an interaction with the surrounding water.

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[SAIL3]

the day before thanksgiving, the two cooks decided to check in on their beloved bird and were shocked to see the sorry state of the turkey.
They realized immediately that they had to make other plans for the thanksgiving dinner.
So now their challenge was how to make spam in a can look like and taste like turkey..
All's well that end well..so the turkey's life was spared.

So what lessons in life are we to learn from this saga??

thin is good?

fight or flight?..choose flight!

don't sweat the small stuff, but really really sweat the big stuff! etc.

Happy thanksgiving to all!!

 

[swall]

I'd take a Spam turkey over a tofu turkey any day!