Which property primarily affects hydrostatic pressure and inertia in liquids?

Which property primarily affects hydrostatic pressure and inertia in liquids?

• A. Viscosity
• B. Density
• C. Compressibility
• D. Temperature

Answer: (B)

Hydrostatic pressure and inertia in liquids are governed by how much mass sits in a given volume. That mass per unit volume is density. At any depth, the pressure from the fluid column is given by ρ g h, so a denser liquid (higher ρ) pushes harder at the same depth. Inertia, the resistance to changes in motion, also scales with mass; for a given volume, more mass means more inertia, so a higher-density liquid resists acceleration more strongly. Viscosity relates to how the fluid flows and damps motion, which is different from the static pressure itself. Compressibility and temperature can influence density and flow in other ways, but the direct factor determining both hydrostatic pressure and inertia is density.

Hydrostatic pressure and inertia in liquids are governed by how much mass sits in a given volume. That mass per unit volume is density. At any depth, the pressure from the fluid column is given by ρ g h, so a denser liquid (higher ρ) pushes harder at the same depth. Inertia, the resistance to changes in motion, also scales with mass; for a given volume, more mass means more inertia, so a higher-density liquid resists acceleration more strongly. Viscosity relates to how the fluid flows and damps motion, which is different from the static pressure itself. Compressibility and temperature can influence density and flow in other ways, but the direct factor determining both hydrostatic pressure and inertia is density.