14. A wooden block floating in a cylindrical vessel with a base area of $\mathrm{S}=25 \mathrm{~cm}^2$, partially filled with water, had a small stone placed on it. As a result, the block remained afloat, and the water level in the vessel rose by $h_{1}=1.5 \mathrm{~cm}$. Then the stone was removed from the block and dropped into the water. The stone sank, and the water level in the vessel rose by $h_{2}=0.5$ cm. Find the average density of the stone material, given that the density of water $\rho=1$ g/cm$^3$.
14. When the stone was placed on the block, the pressure on the bottom of the vessel increased by the amount

$$
p_{1}=\rho g h_{1}
$$

and the force of pressure on the bottom of the vessel increased, on the one hand, by the weight of the stone $\mathrm{mg}$, where $\mathrm{m}$ is the mass of the stone, and on the other hand, by the amount $p1 S$. From the equality

$$
m g=p_{1} s
$$

We find:

$$
m=\rho h_{1} S
$$

The submerged stone will displace a volume $h_{2} s$ of water, equal to its own volume, that is, the volume of the stone

$V=h_{2} S$.

From the relations (1) and (2) we find the average density of the stone:

$$
\rho_{\mathrm{s}}=\frac{m}{V}=\rho \frac{h_{1}}{h_{2}}=3 \rho=3 \frac{\mathrm{r}}{\mathrm{cm}^{3}}
$$