archimedes principle debunked, confusing you :)
 

you have one meter stick of density 0.9

how does it float on water horizantally or vertically?

yeah horizontally the metacentrum thing

if you put it vertical from where does it get the energy to flotate horizontally if in both cases evacuates same amount of water?

do you realize the only thing they did with you is reinforce your faith and kill your critic spirit by going to college?

i know ive spent the last 20 years there :)

i lost you to the last part:grin:

why if you put a wood long stick on water it floats horizontal and not vertical if in both cases evacuates same water?

well the answer and to think like this is what keeps me failing physics :) is this:

with wood the lower its in water the more potential energy it has

the cog of the stick is lower vertically than horizontally and mother nature if it can its generous and spends potential energy

but the thought worth having its that in both cases it evacuates same water so the force should be equal

but the the only equal force is the vertical staright force in both cases

but theres a twist rotational force that only appears with the stick vertical

therefore with the same force of buoyancy according archimedes. The force is actualy stronger in one case than the other

but dont worry i wont tell this my physics teacher as i wont tell my psichiatrist that all tvs are stereovision ;)

edit:

or i could be all wrong because if you put a 0.5 density stick cog will be in same position however it floats but id say it will float horizonatlly

i know ill confuse you cause im confused and im finishing nautic engineering :)

center of gravity

Yup. The centre of gravity of the stick id presumably half way along its length, while the centre of buoyancy is half way along the length of the immersed portion - which puts it below the CoG. This is dynamically unstable., as any slight tilt will tend to increase. If the stick is horizontal, it may roll on its own long axis to reach the most stable position (which will depend on the cross section), but any tilt along its length will be self correcting.

For many real floating objects, the situation is more complex than this - a ship can have multiple 'stable' orientations, and the 'funnel up' one may actually be the least stable. See also http://en.wikipedia.org/wiki/Metacentre#Metacenter.

yes but think this:

a floating stick of density 0.5 what will happen here:

either center of gravity of the stick and level of water doesnt change wetaher the stick floats horizontal or vertical

then how can go from one position to other if no energy was spent?

center of gravity....or your stick must have an equal length/width/depth.....i.e. is a cube shaped stick.......simples

more surface tension if it floats horizontally...

My brain hurts! I think I need to draw a diagram...

the latest theories of sentience, in inanimate objects. suggest that due to quantum organisation of matter, into complex systems, at the sub atomic level...
all matter may posses some level of sentience.....the stick will attain the most comfortable and relaxing position, vis a ve, the gravity vectors...the stick is achieving a more relaxing position, and may even have dozed off.

as sticks evolve, they are likely to form viable complex societys..leading eventually to the horror of a world stick war....we have been warned..jim

...ditto, what they said...

if this doesnt confuse you as it confuses me well....

im sorry your critic spirit got killed by the educative syustem :(

http://i40.photobucket.com/albums/e2...Imagen0082.jpg

FROM WHERE DOES IT GET THE ENERGY TO GO FROM ONE POSITION TO OTHER¡¡¡¡

Why have you put the CoG on the waterline?

because it has density = o.5 so it floats exactly in the midle :)

thanks for listening litle grasshoper :)

ok genious.....what about the half thats under water.....it will still want to 'float' so it will turn itself until it reaches some sort of stability....i.e. it will lay itself flat

exactly you got it but water spends energy lowering the level of it or moving the stick cog

but neither happens

an isentropic work in nature?

edit:

so maybe you agree that in both cases the force of the water on the stick aint the same?

You obviously don't understand 'displacement', a ship made of steel is much denser than water, it floats because it displaces a certain amount of water which creates a force pushing it 'up'.....same with the stick, if you float it on its end it will push up until the CoG is above the water line (unstable) so it falls on its side and everything is balanced out.....simples

yeah we agree totally

but you havent answered my question?

is the force of buoyancy equal in both cases?

edit:

not to be concited but remember im 4 subjects away from becoming a nautic engineer, i had to do quite some problems on this

Raaaid with your 50% density example, the CoG of the object is goung to be on the waterline, as you state. The centre of buoyancy however is going to be half way down the immersed section - and as such at different levels in the two examples. The energy for the move comes from the centre of gravity of the displaced water being lower in the case where the object is floating horizontally.

Buoyancy isn't really a force....it's a property, which makes it constant for any given object, displacement on the other hand is a force and it is the same in both cases, this whole issue is one of stability and moments.

"The energy for the move comes from the centre of gravity of the displaced water being lower in the case where the object is floating horizontally"

yeah you got it, im pretty sure thats the way energy works there

but then you have to agree than in one case the force of buoyancy is greater than the other

BUT IN BOTH CASES EQUAL AMOUNT OF WATER IS DISPLACED

who hasnt memorized this?

"the principle states that the buoyant force on an object is going to be equal to the weight of the fluid displaced by the object"

now wouldnt you call this principle false then?

it expects equal force in both cases since the displaced water is equal

but andy just nailed i the key is that nature if it can takes the cogs down

edit:

i knew here would be a better place to discuss this than an science forum really good thinkers people here :)

could petrol companies sponsor science?

check this out andy do you think its worth to render in a phyics simulator?

http://i40.photobucket.com/albums/e2...Imagen0083.jpg

the mass of the stick may be the same in both configurations... but in the vertical it transposes its mass into a smaller footprint compared to the amount transposed when in the horizontal.
stable = COG sitting just below the waterline

have a paddle at the beach.... stretch out and you float, curl up and you sink