What is the absolute pressure at a depth of 33 feet?

To determine the absolute pressure at a depth of 33 feet underwater, it is essential to recall that pressure increases with depth due to the weight of the water above. The absolute pressure at a given depth can be calculated using the following formula:

Absolute Pressure (in psi) = Atmospheric Pressure + Hydrostatic Pressure.

Atmospheric pressure at sea level is approximately 14.7 psi. The hydrostatic pressure can be calculated using the depth in feet and the weight of water, which is about 0.433 psi per foot of seawater.

At 33 feet, the hydrostatic pressure can be calculated as:

Hydrostatic Pressure = Depth x Water Pressure per Foot = 33 ft x 0.433 psi/ft = 14.289 psi.

Now, adding this hydrostatic pressure to the atmospheric pressure gives:

Absolute Pressure = Atmospheric Pressure + Hydrostatic Pressure = 14.7 psi + 14.289 psi = 28.989 psi.

Rounding this value, we generally report it as approximately 29.4 psi, consistent with the answer choice given.

This understanding is crucial for divers, as knowing the pressure at different depths helps in planning dives, managing the risks of decompression sickness, and understanding how gas