Posted by Melissa on Tuesday, August 9, 2011 at 10:07pm.
A piece of wood is floating at the surface of some water as illustrated (the diagram is not to scale). The wood has a circular cross section and a height h = 4.0 cm. The density of water is 1.00 g/cm3. The distance y from the surface of the water to the bottom of the wood is 3.0 cm. The density of the wood is (in g/cm3):
Question 1 options:
A)Impossible to determine because the area of the cross section is not given.
B)12
C)0.75
D)0.25

PHYSICS  bobpursley, Tuesday, August 9, 2011 at 10:13pm
the volume underwater is area*h=area*3
mass of water displced=densitywater*volume
= 1g/cm^3*area*3
This is equal to the weight of the wood:
weight wood=densitywood*volume
= densitywood(area*4cm)
set them equal
1*area*3=densitywood*area*4
density wood=.75g/cm^3