Calculating Density of Oil Using Buoyant Force Formula | Homework Help

AI Thread Summary
To calculate the density of oil using the buoyant force formula, the block of wood, which has a density of 0.67 g/cm³ and is 90% submerged, provides the necessary information. The buoyant force equation relates the density of the oil to the volume of the wood submerged. By recognizing that the volume of oil displaced equals 0.9 times the volume of the wood, the density of oil can be derived. The discussion highlights the importance of equilibrium in buoyancy calculations, clarifying that the buoyant force equals the weight of the displaced fluid. The final calculation simplifies to finding the ratio of the wood's density to the submerged volume fraction.
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Homework Statement



Buoyant force. A block of wood floats in
oil with 90.0% of its volume submerged. What
is the density of oil? The density of the block
of wood is 0.67 g/cm3.

Homework Equations



buoyant force = pgV

The Attempt at a Solution



p(oil) V(oil)=p(h20) V(h20)

p(oil)= p(h20) V(h20) / V(oil)

i know that the V(oil) displaced is equal to .9V(h20)

so, p(oil) = .67 V(h20) / .9 V(h20)

do the terms 'V9h20' simply cancel, leaving me with .67/.9? Thanks
 
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h20? hmmm where did you get that from,I hope you don't mean H2O because my friend this problem has no water to be seen!

You need to use the fact that the block is in equilibrium, thus the buoyancy force is equal and opposite to another force... hmmmm what could that be. It's really easy, have another go at a solution.
 
gah i was half working on another problem while typing this one out, sorry for the stupid typo; thanks for the response
 

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