Question

A scuba driver with a local sheriffs office has been assigned the task of retrieving a sunken car in the Red river. The car is believed to have human remains inside. The scuba driver descends to a depth that's 60 feet below the surface of the river and breathes out a stream of bubbles. What is the total gas pressure of these bubbles at the moment they are release? What is the gas pressure in the bubbles when they reach the surface of the river?

Answer 1

The gas is initially in the lungs of the diver, so it has pressure equivalent to the atmospheric pressure. Next, when the diver dives, an additional pressure is exerted by the water. Before, computing this pressure, we convert the depth into meters, which is 18.3 meters.
Using,
pressure = density * gravity * height
P = 1,000 * 9.81 * 18.3
P = 179,523 Pa

The atmospheric pressure is 101,325 Pa. The total pressure of the gas bubbles underwater will be:
179,523 + 101,325

280,848 Pa underwater and 101,325 Pa at the surface.