Physics Questions and Answers

Start Your Free Trial

At sea level, what is the approximate value of atmospheric pressure in Pa, in mmHg and in atm? (where g = 10 N/kg)

Expert Answers info

pohnpei397 eNotes educator | Certified Educator

calendarEducator since 2009

write35,413 answers

starTop subjects are History, Literature, and Social Sciences

At sea level, the approximate value of atmospheric pressure in those units of measure is as follows:

  • 101.3 kPa which is how it is usually expressed.  In pascals, it is 101325 pascals.  The first of these units (kilopascals) is usually used because pascals are such a small unit that it is much less cumbersome to express the measurement in kilopascals.
  • In mmHg (milimeters of mercury), the measure is 760
  • In atm (atmospheres) it is 1 atm.

These are a standard set of measures.  The actual measurement will, of course, vary with weather conditions, which is why barometers work.

check Approved by eNotes Editorial

neela | Student

The atmospheric pressure at the sea level is equal to 760 mm of height of the column of mercury. With this height  of 760 mm of mecury, the atmospheric pressure  is equal to the weight force of the 760 mm of mercury. So, the pressure  P = weight of mecury of occupying a cuboid of 1 sq meter base and height of 0.76 meter = 0.76 cubic meter* density of mecury*10N/Kg

=(0.76cubic meter.)(13534 Kg/cb met)(10N/kg) / sq meter.

=116690.4 N/sq meter.

=116690.4 pascals, is the atmospheric pressure at the sea level, where the acceleration due to gravity is 10N/kg.This is slightly more, as we are to work for the pressure at the location of the sea level where g = 10N/kg,


check Approved by eNotes Editorial
giorgiana1976 | Student

Although 1013.25 mb (760 mm Hg) is considered to  be the standard atmospheric pressure at sea level, it does not mean that the pressure at this level has this value, actually this being 1011 mb.

Since much of the Earth's surface is above sea level, annual average atmospheric pressure at the surface was estimated to be 984.43 mb.

Atmospheric pressure measurement is made by direct reading on barometer with mercury or  metal barometer. The registration of atmospheric pressure is made with Barograph, daily or weekly.In situations where the weather is the distribution of atmospheric pressure at sea level, to the values determined instrumental will suffer correction of level (height=0m and t=150C), temperature correction(reducing to 0C) and correction of latitude(reducing to the average latitude).

Atmospheric pressure is encoded being reduced at sea level,  in mb, symbol PPPP (± 0.1 mb).

check Approved by eNotes Editorial