The two blocks (block 1 with volume V1 = 4 m3 and block 2 with volume V2 = 2 m3) shown in the figure are submerged completely in water so that block 1 rests just below the surface. The two blocks are connected by a thin string of negligible mass and volume. If block 2 has a density 1.5 times that of block 1, what is the density of block 2?