Short answer: depends ... you didn;t write out the whole question did you?chetzread said:
... sure: but you posted in homework so you need to work it out.
That is correct - the buoyant force must be equal to the weight of the floating object (for floating at the surface). But there are other forces happening too - even in perfectly still liquid.
Is it submerged or floating? Submerged means completely immersed in the liquid.chetzread said:
If it is floating in both instances then yes, the buoyant force is the same, but not for the reason you give.chetzread said:
It's floating, so , is my idea correct?haruspex said:
You are correct that the buoyant force is the same if it is floating in both cases, but you have not stated the correct reason.chetzread said:
Not (rho) (V) (g) = same for both case?haruspex said:
Define what you are using V to mean.chetzread said:
Volume of liquid displaced = volume of the part where the object submerged...haruspex said:
Ok, but how do you know that the product Vρ will be the same in both cases? There are two different densities.chetzread said:
No, I assume Buoyat Force for both are same, so, when the density is high, then volume displaced small, then Buoyant Force are same for both cases, so is my idea correct?haruspex said:
Yes. You originally wrote that the buoyant force is the same because Vρ is the same for both, but that's backwards. Vρ is the same because the buoyant force is the same. But why is the buoyant force the same?chetzread said:
No, I mean when the object is floating in less density water, the volume of water displaced by the object is small, when objects is floating in high density water, volume of water displaced by object is small, so in the first case (rho) is small, v is big, in the second case , rho is big, volume of water displaced by object is small, so Buoyant Force for both case are the same... Am I right?haruspex said:
Yes, that is all correct.chetzread said:
The buoyant force is the same in both cases, but what is wrong is the word "so". What you wrote in the first quote above is not the reason that the buoyant forces are the same. There is another reason the forces are the same, and because the forces must be the same, the two submerged volumes are as they are.chetzread said:
If we were to say "yes" or "no" to that question, then we would be "doing your homework for you" - which is not allowed.chetzread said:
Simon Bridge said:
You are not paying attention. I just told you:chetzread said:
For post #15 intuitively, the object float 9/10 in water would be more stable, am I right?Simon Bridge said:
... I never said "water", but, from your experience of objects floating in water you have an intuition that the object that floats with the most submerged will be the most stable, where everything else is the same. In other words: the worse it floats the more stable it is. This is a reasonable statement to make.chetzread said:
The object which submerged more is more stable because if we apply the force in arbitrary direction to the object, the object which submerged more is less likely to turn over...Simon Bridge said:
Well done - do you know why this is?chetzread said:
Liquid A is denser...Simon Bridge said:
... because? Show your reasoning?chetzread said:
... so, just making sure we are on the same page: which liquid is that: liquid A or liquid B?
I maybe misunderstood what you said. Do you mean in liquid A, only 1/10 of the object float on surface? If so, then liquid A is less denseSimon Bridge said:
Can you continue your explanation?Simon Bridge said:
Liquid A is less dense, can you continue?Simon Bridge said:
Right, so based upon your post #20, should it be more stable in the higher density liquid or the lower density one?chetzread said:
Less density liquid cause the object to become more stable, so the ans for post #14 is the object would be less stable when it's submerged in higher density liquid?haruspex said:
Yes, that would generally be true.chetzread said:
So, the reason that the object is less stable in more dense water is because when the object float higher in liquid, it has more tendency to turn over?haruspex said:
Yes. But as I posted, that is only the general trend. There may be exceptions according to shape.chetzread said:
Exception according to shape? Can you explain further?haruspex said:
Not specifically. I just wanted to alert you to the fact that the topic is subtler than may appear, that it might not actually be true that the object would always be more stable in the lighter fluid, and that even if it is a rigorous proof would not be easy.chetzread said:
