Question

what is atmospheric pressure

Answer 1

Atmospheric pressure is the pressure exerted by the weight of the atmosphere, which at sea level has a mean value of 101,325 pascals.

Answer 2

Atmospheric pressure, sometimes also called barometric pressure, is the pressure within the atmosphere of Earth. The standard atmosphere is a unit of pressure defined as 1013.25 mbar, equivalent to 760 mmHg, 29.9212 inches Hg, or 14.696 psi