How is absolute pressure expressed?

Absolute pressure is measured relative to a perfect vacuum and typically includes the atmospheric pressure acting on the surface. Standard atmospheric pressure at sea level is approximately 14.7 psi (pounds per square inch) or 1 ata (atmospheric absolute). Therefore, expressing absolute pressure as 14.7 psi corresponds directly to 1 ata.

The significance of this is that absolute pressure is the total pressure experienced, including both the atmospheric pressure and any additional pressure from a fluid column or other sources. In diving and other applications where pressure is critical, being aware of absolute pressure helps in understanding both the physical forces at play and the physiological responses of divers.

Options expressing values significantly different from 14.7 psi/1 ata do not accurately represent the definition of absolute pressure under standard conditions. Thus, recognizing that 14.7 psi and 1 ata is the standard measure for atmospheric pressure is key to understanding this concept in dive physics.