college physics
posted by josh .
find the weight of a piece of wood with a density of .5 g/cm cubed. which when attached to a 5kg stone in water it will sink. the density of the stone is 3g/cm cubed

ok, when sinking
weight of wood+weightstone=weight of waterdiaplaced
MassWood*g+5g=densitywater(volume stone+volumewood)*g
volumeWood=MassWood/.5g in cm^3
volumestone=5000g/3g in Cm^3
masswood=1g/cm^3(5000/3+Masswood/.5)5
solve for mass wood.