what is atmospheric pressure
Answers
Answer:
That pressure is called atmospheric pressure, or air pressure. It is the force exerted on a surface by the air above it as gravity pulls it to Earth. Atmospheric pressure is commonly measured with a barometer. ... One atmosphere is 1,013 millibars, or 760 millimeters (29.92 inches) of mercury.
Explanation:
NASA photo showing Earth's atmosphere at sunset, with Earth silhouetted
Blue light is scattered more than other wavelengths by the gases in the atmosphere, surrounding Earth in a visibly blue layer when seen from space onboard the ISS at an altitude of 335 km (208 mi).[1]
Composition of Earth's atmosphere by volume, excluding water vapor. Lower pie represents trace gases that together compose about 0.043391% of the atmosphere (0.04402961% at April 2019 concentration [2][3]). Numbers are mainly from 2000, with CO
2 and methane from 2019, and do not represent any single source.[4]
The atmosphere of Earth is the layer of gases, commonly known as air, retained by Earth's gravity, surrounding the planet Earth and forming its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing for liquid water to exist on the Earth's surface, absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night (the diurnal temperature variation).
By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases.[8] Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere. Air composition, temperature, and atmospheric pressure vary with altitude, and air suitable for use in photosynthesis by terrestrial plants and breathing of terrestrial animals is found only in Earth's troposphere and in artificial atmospheres.
Earth's atmosphere has changed much since it's formation as primarily a hydrogen atmosphere, and has changed dramatically on several occasions -- for example, the Great Oxidation Event 2.4 billion years ago, greatly increased oxygen in the atmosphere from practically no oxygen to levels closer to present day. Humans have also contributed to significant changes in atmospheric composition through air polution, especially since industrialisation, leading to rapid environmental change such as ozone depletion and global warming.
Answer:
The pressure exerted by the weight of the atmosphere, which at sea level has a mean value of 101,325 pascals (roughly 14.6959 pounds per square inch).
Explanation:
That pressure is called atmospheric pressure, or air pressure. It is the force exerted on a surface by the air above it as gravity pulls it to Earth. Atmospheric pressure is commonly measured with a barometer. ... One atmosphere is 1,013 millibars, or 760 millimeters (29.92 inches) of mercury.