What is Earth's surface (sea level)? Its pressure is 14.7 psi. That is what is the number of ft.
14.7 psi is the air pressure at the earth's surface. That is the pressure exerted by a 1-sq-in column of air reaching up to space.
The earth's atmosphere is about 300 miles thick. That air presses down everywhere with a weight of 14.7 pounds on every square inch of the surface.
To determine the number of feet corresponding to Earth's surface pressure of 14.7 pounds per square inch (psi), we need to convert psi to another pressure unit before converting it to feet.
First, we'll convert psi to another widely-used pressure unit, such as atmospheres (atm).
1 psi is approximately equal to 0.068046 atmospheres. So, we can calculate:
14.7 psi * 0.068046 atm/psi ≈ 0.9997 atm.
Now that we have the pressure in atmospheres, we can proceed to convert it to the corresponding pressure at Earth's surface level.
At sea level, the average atmospheric pressure is approximately 1 atmosphere. Hence, the pressure of 0.9997 atm can be considered very close to 1 atmosphere.
Next, we'll convert this pressure to feet. However, the conversion from pressure to feet depends on the specific context or medium in which the pressure is acting (e.g., fluid, gas, or water).
If we assume that you are referring to the pressure exerted by a fluid, like water, we can use the hydrostatic pressure equation:
Pressure = Height × Density × Acceleration due to gravity,
Where:
- Pressure is in pounds per square foot (psf),
- Height is in feet,
- Density is in slugs per cubic foot (slug/ft³), and
- Acceleration due to gravity is approximately 32.174 ft/s².
Assuming water as the fluid medium, the density of water is approximately 62.4 pounds per cubic foot (lb/ft³). Plugging in the values:
1 atm = Height × 62.4 lb/ft³ × 32.174 ft/s².
Rearranging the equation to solve for Height:
Height = 1 atm / (62.4 lb/ft³ × 32.174 ft/s²) ≈ 0.491 ft.
Therefore, Earth's surface pressure of 14.7 psi is approximately equivalent to 0.491 feet when considering the pressure exerted by a fluid (like water).