Gasoline and an unknown liquid are poured into the communicating vessels. The height of the gasoline level is 10 cm

Gasoline and an unknown liquid are poured into the communicating vessels. The height of the gasoline level is 10 cm, and the height of the liquid is 7 cm. Determine the density of the liquid, the density of gasoline is 700kg / m3.

The pressures of the columns of liquids in communicating vessels balance each other.

Hence, ρх g hх = ρb g hb,

where ρх is the density of the unknown liquid, kg / m3; ρb is the density of gasoline, ρb = 700 kg / m3; g – acceleration due to gravity, g = 9.8 m / s2; hх – the height of the layer of the unknown liquid, hх = 7 cm = 0.07 m; hb is the height of the gasoline layer, hb = 10 cm = 0.1 m.

Thus, the required density ρх:

ρх = ρb hb / hх = 700 × 0.1 / 0.07 = 1000 kg / m3.

Supposedly, the unknown liquid is water.