Final answer:
The pressure of air at sea level is 1 atm (760.0 mm Hg). At 66 ft underwater, the pressure increases by 1 atm for every 33 ft, totaling approximately 3 atm at 66 ft. Above water at 66 ft altitude, the pressure essentially remains the same as at sea level unless affected by weather or altitude changes.
Step-by-step explanation:
The pressure of air at sea level is generally accepted as 760.0 mm Hg, which is equivalent to 1 atm (atmosphere). For calculations involving the pressure of air under the sea (at depth), we typically use the fact that every 33 feet of sea water exerts an additional pressure of about 1 atm in addition to the atmospheric pressure at sea level. So, at 66 ft underwater the pressure would be approximately:
- Pressure at sea level (1 atm) plus
- Pressure due to 33 ft of water (1 atm)
- Pressure due to another 33 ft of water (1 atm)
Which totals to 3 atm.
However, since the student's question does not clarify whether we are examining the air pressure above water or under water at 66 ft, the pressure at sea level (1 atm) would remain the same at 66 ft above sea level, unless we consider variations due to weather or altitude changes.