What is the absolute pressure at 99 feet in salt water expressed in atmospheres absolute?

To determine the absolute pressure at a depth of 99 feet in salt water, one must consider both the pressure exerted by the water column above and the atmospheric pressure at the surface.

In salt water, the pressure increases approximately by 0.445 psi for every foot of depth. At 99 feet, the pressure due to the water column would be calculated as follows:

99 feet x 0.445 psi/foot = 44.055 psi

Now, we also have to add the atmospheric pressure at the surface, which is typically about 14.7 psi. Therefore, the total pressure at depth can be calculated:

44.055 psi (water pressure) + 14.7 psi (atmospheric pressure) = 58.755 psi

To convert this pressure into atmospheres absolute (ATA), we divide by the pressure equivalent of 1 ATA, which is approximately 14.7 psi:

58.755 psi ÷ 14.7 psi/ATA ≈ 4 ATA

Hence, at a depth of 99 feet in salt water, the absolute pressure is approximately 4 ATA. This value includes both the pressure exerted by the water and the atmospheric pressure above the water, providing an accurate representation