Barometric pressure is equivalent to_____________________?
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Answer: A. 760 mm Hg
Explanation
Standard barometric pressure is defined as the pressure exerted by a mercury column measuring exactly 760 millimeters. This classic standard corresponds to one atmosphere of pressure measured at sea level under standard conditions. Mercury barometers use this height measurement as the benchmark for atmospheric pressure reporting. Evangelista Torricelli invented the mercury barometer to measure atmospheric pressure variations. Standard atmospheric pressure equals one hundred one thousand three hundred twenty-five pascals or 760 mm Hg. Density of mercury allows barometers to remain compact compared to water-filled pressure measurement columns.
Meteorologists report daily weather barometric pressures in millimeters or inches of mercury and hectopascals. Aviation altimeters calibrate altitude readings against standard barometric pressure reference tables. Thermodynamic laboratory experiments require recording barometric pressure to correct gas volume calculations. Zero millimeters of mercury represents a complete vacuum with no atmospheric pressure present. A value of 735.6 millimeters of mercury corresponds to older engineering technical atmospheres rather than standard. One millimeter of mercury represents a very low vacuum pressure rather than standard atmospheric conditions.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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