Thanksgiving turkey
Thanksgiving turkey
(OP)
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?
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?






RE: Thanksgiving turkey
We once raised a 60lb turkey. That sucker took 8 hours to cook. It kept springing the oven rack so we supported it with 2x4 blocking.
As for the buoyancy. No it will be the same. The mass hasn't moved outside of the sub.
Myth busters covered this.(except with pigeons and then a toy helicopter) The air from the wings is pushing down with a force equal to the mass lifted.
RE: Thanksgiving turkey
RE: Thanksgiving turkey
RE: Thanksgiving turkey
RE: Thanksgiving turkey
RE: Thanksgiving turkey
BTW - Port is right!!
RE: Thanksgiving turkey
TTFN
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RE: Thanksgiving turkey
RE: Thanksgiving turkey
I don't fully understand how a local pressure differential at the wing of the turkey can translate into a gravity event for the submarine as awhole...
IR..if the turkey stops generating lift for a second or two(begins to freefall), is the equilibrium condition still vaild?
RE: Thanksgiving turkey
So what happens once all the guys catch, and eat said turkey?
RE: Thanksgiving turkey
However, one can possibly look at it as a conservation of momentum problem, so there are impulsive events that are directed at the submarine, as the turkey flies or changes direction.
I completely agree that such impulses are absurdly tiny, given that something like the SSN John Warner has a gross weight of 7800 tons.
TTFN
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RE: Thanksgiving turkey
It does not matter if the turkey is flapping or gliding. The wings vector air downwards to generate lift. If the turkey were to switch from flying to ballistically hurtling for a bit, there would be an increase in the sub's bouyancy followed by a reduction in the bouyancy when the turkey either crashed or generated extra lift to climb back to his original altitude.
RE: Thanksgiving turkey
FedEx flies baby chicks all over the US and they still charge by the pound - because they KNOW!
RE: Thanksgiving turkey
Using equivalent static analysis, the Turkey Load, TL = W x Ct
W = 100 lbs
Ct = St / R, where St = Design turkey response acceleration parameter (we'll use 1.5 for a fat yet agile turkey) and R = turkey table response modification factor(not given but we'll assume 3.5 for ordinary moment resisting steel table frame design).
So TL = 43 lbs over the fundamental buoyancy period of the submarine, T.
Since T requires an incoherent model we will use the approximate period, Ta = Cs h^x where Cs = approximate period structural parameter (0.01 for submersed steel cylinders), h = length of the submarine (560 ft for a typical Ohio class) and x = approximate period exponent parameter (0.95 for submersed steel cylinders)
So T = Ta = 4.08 seconds
In conclusion, a Turkey Load of 43 lbs will unbalance the submarine for a period of 4.08 seconds until equilibrium is returned.
RE: Thanksgiving turkey
Please advise what engineering school you graduated from (if you did). My son needs to make his choice soon ...
RE: Thanksgiving turkey
the turkey is flying around the cabin and this went on for 5 days and nights, no rest and no food, as a result the turkey began to lose weight and strength until finally it collapses back on the table, after having lost 50lbs and too exhausted to care anymore, come what may(kinda like how some design projects wind up)...
same question: has the equilibrium/buoyancy of the submarine changed?
RE: Thanksgiving turkey
Probably one of those old diesel subs where they had to bring in livestock for food since they had no modern refrigeration. Serious odor problems on board.
RE: Thanksgiving turkey
This gives the equation -->
Total weight = 2.5*Delta Turkey
Also this particular turkey lost 50 lbs (Delta turkey = -50)
Because we know all equations are reversable this gives us
Toal wt = 2.5 (-50)=-125
Therefore the sub lost 125 lbs thus changing the boyancey.
RE: Thanksgiving turkey
RE: Thanksgiving turkey
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.
RE: Thanksgiving turkey
No effect on buoyancy due to this factor alone.
RE: Thanksgiving turkey
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
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RE: Thanksgiving turkey
RE: Thanksgiving turkey
TTFN
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RE: Thanksgiving turkey
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/
RE: Thanksgiving turkey
Andries
RE: Thanksgiving turkey
RE: Thanksgiving turkey
RE: Thanksgiving turkey
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.
RE: Thanksgiving turkey
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...
RE: Thanksgiving turkey
ht
RE: Thanksgiving turkey
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.
RE: Thanksgiving turkey
Turkeys are not rockets, so they cannot move without pushing against something, be it air or the floor.
TTFN
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RE: Thanksgiving turkey
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/
RE: Thanksgiving turkey
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..
RE: Thanksgiving turkey
RE: Thanksgiving turkey
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
RE: Thanksgiving 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!!
RE: Thanksgiving turkey
RE: Thanksgiving turkey
How does that rank with a turducken?
http://en.wikipedia.org/wiki/Turducken
TTFN
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RE: Thanksgiving turkey
What are you Mr Carlson?
RE: Thanksgiving turkey
Its gonna take a while and tomorrows the big day.
RE: Thanksgiving turkey
"Good to know you got shoes to wear when you find the floor." - Robert Hunter