posted by jessica on .
One cm of a 10-cm-long rod is made of metal, and the rest is wood. The metal has a density of 5000kg/m^3 and the wood has a density of 500kg/m^3. When the rod is set into pure water, the metal part points downward. How much of the rod is underwater?
well, you know the metal will all be underwater. So the question is how much wood is under to support the weight of the metal.
bouyancy of wood= h*density water*area*g
that has to equal the weight of the entire rod.
dividing out area, g; divideing by density water.
h= (.1 spgrmetal)/(1+sprgwood)= about .5/(1.5)=33cm ?
check my work.