i seem to be stuck on a problem which involves fluids of 2 different densities, and an object floating in/on them. A block of wood is floating in a jar of water. oil is then poured onto the water. how can i calculate the mass of "the fluid displaced" when it is composed of 2 different fluids, and i have no idea how large the jar is? i don't think i should average their densities, but i keep getting a wrong result.(adsbygoogle = window.adsbygoogle || []).push({});

for a floating (partially submerged) object, i can see that

FB = mg = (fraction submerged) (weight of fluid displaced by entire object)

= (fraction) (rho of fluid * Volume of object * g)

i have used this to find the fraction of an object which is above or below the surface. how can i change it to apply to 2 fluids with 2 different densities?

the specifics given:

rho(wood) = 500 kg/m^3

rho(oil) = 600 kg/m^3

v(wood) = (.01m)^3

question asks how deep oil layer is when it is 4 cm below the top of the block.[/CODE]PHP:

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Fluid mechanics and buoyancy

**Physics Forums | Science Articles, Homework Help, Discussion**