Formulas
- Density: ρ = m ÷ V. Water is 1,000 kg/m³ (1 g/cm³).
- Pressure: p = F ÷ A, in pascals (Pa = N/m²).
- Pressure under a liquid: p = ρ·g·h.
Examples
- 2 kg of a liquid filling 2.5 L: density 800 kg/m³ (0.8 g/cm³). It floats on water.
- A 600 N force on 0.03 m²: pressure of 20,000 Pa (20 kPa).
- 10 m under fresh water: 98,100 Pa from the water, almost 1 atm. Adding the air above, the absolute pressure is about 2 atm.
Frequently asked questions
Why do things float?
An object floats when it is less dense than the liquid. Ice (about 917 kg/m³) floats on water.
How many pascals is 1 atm?
101,325 Pa, or about 1.013 bar.
How do I convert g/cm³ to kg/m³?
Multiply by 1,000. 2.7 g/cm³ (aluminum) = 2,700 kg/m³.
See also
Results are estimates for information only and are not financial, legal or medical advice. Rates, taxes and fees vary — confirm with a professional or your lender.