Question

Почему нельзя рассчитывать давление воздуха, используя формулы для расчета давления в жидкости​

Answer 1

Ответ:

необходимо знать плотность и высоту столба жидкости или газа. Но у атмосферы нет четкой верхней границы, а плотность атмосферного воздуха уменьшается с ростом высоты.

Answer 2

Why can't air pressure be calculated using formulas for liquid pressure?

Air pressure and liquid pressure are two different concepts and cannot be calculated using the same formulas. Here's why:

1. Difference in Molecular Structure: Air is a gas, while liquids are composed of closely packed molecules. The molecular structure of gases and liquids is fundamentally different, leading to variations in their behavior and properties.

2. Compressibility: Gases, including air, are highly compressible, meaning their volume can change significantly under pressure. On the other hand, liquids are nearly incompressible, and their volume remains relatively constant even under high pressure.

3. Equation of State: The equation of state for gases, such as the ideal gas law, relates pressure, volume, and temperature. However, this equation does not hold true for liquids. Liquid pressure is determined by factors like depth, density, and gravitational acceleration, which are not applicable to gases.

Therefore, the formulas used to calculate pressure in liquids, such as Pascal's law or the hydrostatic pressure equation, cannot be directly applied to calculate air pressure. Air pressure is typically measured using devices like barometers or manometers, which are specifically designed to measure gas pressure.