Question

A scuba diver with a local Sheriff’s office has been assigned the task of retrieving a sunken vessel in the Ocean. The vessel is believed to have human remains inside. The scuba diver descends to a depth that is 60 feet below the surface of the ocean and breathes out a stream of bubbles. What is the total gas pressure of these bubbles at the moment they are released? What is the gas pressure in the bubbles when they reach the surface of the river?

Answer 1

First, we convert the depth of the water into meters. This is:
60 feet = 18.3 meters

Now, we compute the additional pressure exerted due to the water, which is given by:
Pressure = density * gravitational field strength * height
P = 1000 * 9.81 * 18.3
P = 179.5 kPa

The atmosphere pressure is 101.325 kPa
The pressure of the gas bubbles 60 feet under water will be:
179.5 + 101.325 = 280.825 kPa

The pressure at the surface of the water will be equal to the atmospheric pressure, 101.325 kPa.

Because of this decrease in external pressure as gas bubbles rise, they are seen to expand.