(1) As can be seen from the figure, when the depth of the poured liquid is 0, the pressure of the block at the bottom of the container is F=G=20N.

When the depth of the poured liquid h=4cm=0.04m, the pressure of the block at the bottom of the container f ′ =15n, while f ′ = g-f floats.

∴F float =G-F'=20N- 15N=5N,

∫F float =ρ liquid v row g=ρ liquid Shg,

∴ density of liquid:

ρ liquid =F floating SHG = 5n10x10x10? 4 m2×0.04m× 10N/kg = 1.25× 103kg/m3；

(2)∫G = mg =ρVg，

Density of block:

ρobject = GVG = 20n 10× 10× 10× 10？ 6 m3× 10N/kg = 2× 103kg/m3，

∵ ρ substance >ρliquid,

When the depth of the poured liquid is h ′ =12 cm, the wood block will be immersed in the liquid and sink to the bottom of the container.

Pressure at the bottom of the container:

F pressure =G-F floating' =20N-ρ liquid VG = 20n-1.25x103kg/m3×10x10x.

Therefore, the answer is:1.25x103kg/m3; 7.5N。