Hydrostatics: solving for density.

[Lavabug]

Homework Statement

A block of wood floats in water with 2/3 of its volume submerged. In oil, it does so with 9/10 of it submerged. Find the density of the block of wood and the oil in terms of water's density.

The Attempt at a Solution

Setting the equilibrium condition (net force = 0) I get:

\rho(wood) = 2/3 \rho(water)

then \rho(oil) = 10/9 \rho(wood) which is = 20/27 \rho(water)

So in increasing order of density, I've got: wood < oil < water.

Just wanted to check if this was correct, thanks.

 

[Doc Al]

Looks good to me.