What is air pressure?

Answer: It is the weight of air molecules pressing down on the earth.

Explanation: Without air, then their would be no living creatures roaming around on earth.

The air around you has weight, and it presses against everything it touches. 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. In a barometer, a column of mercury in a glass tube rises or falls as the weight of the atmosphere changes. Meteorologists describe the atmospheric pressure by how high the mercury rises.

An atmosphere (atm) is a unit of measurement equal to the average air pressure at sea level at a temperature of 15 degrees Celsius (59 degrees Fahrenheit). One atmosphere is 1,013 millibars, or 760 millimeters (29.92 inches) of mercury.

Atmospheric pressure drops as altitude increases. The atmospheric pressure on Denali, Alaska, is about half that of Honolulu, Hawai'i. Honolulu is a city at sea level. Denali, also known as Mount McKinley, is the highest peak in North America.

As the pressure decreases, the amount of oxygen available to breathe also decreases. At very high altitudes, atmospheric pressure and available oxygen get so low that people can become sick and even die.

Mountain climbers use bottled oxygen when they ascend very high peaks. They also take time to get used to the altitude because quickly moving from higher pressure to lower pressure can cause decompression sickness. Decompression sickness, also called "the bends", is also a problem for scuba divers who come to the surface too quickly.

Aircraft create artificial pressure in the cabin so passengers remain comfortable while flying.

Atmospheric pressure is an indicator of weather. When a low-pressure system moves into an area, it usually leads to cloudiness, wind, and precipitation. High-pressure systems usually lead to fair, calm weather.

Vocabulary

Term Part of Speech Definition

air

noun  

layer of gases surrounding Earth.

aircraft

noun  

vehicle able to travel and operate above the ground.

air pressure

noun  

force pressed on an object by air or atmosphere.

altitude

noun  

the distance above sea level.

atmosphere (atm)

noun  

(atm) unit of measurement equal to air pressure at sea level, about 14.7 pounds per square inch. Also called standard atmospheric pressure.

atmospheric pressure

noun  

force per unit area exerted by the mass of the atmosphere as gravity pulls it to Earth.

barometer

noun  

an instrument that measures atmospheric pressure.

Celsius scale

noun  

scale for measuring surface temperature, used by most of the world, in which the boiling point of water is 100 degrees.

cloud

noun  

visible mass of tiny water droplets or ice crystals in Earth's atmosphere.

decompression sickness

noun  

serious condition resulting from gases forming tiny bubbles in the bloodstream as a body adjusts to a major change in atmospheric pressure. Also known as DCS, divers disease, and the bends.

exert

verb  

to force or pressure.

Fahrenheit scale

noun  

scale for measuring surface temperature used by Belize, Liberia, Myanmar, and the United States.

force

noun  

power or energy that activates movement.

gravity

noun  

physical force by which objects attract, or pull toward, each other.

high-pressure system

noun  

weather pattern characterized by high air pressure, usually as a result of cooling. High-pressure systems are usually associated with clear weather.

low-pressure system

noun  

weather pattern characterized by low air pressure, usually as a result of warming. Low-pressure systems are often associated with storms.

mercury

noun  

chemical element with the symbol Hg.

mercury barometer

noun  

tool that determines atmospheric pressure by measuring how much mercury moves in a glass tube.

meteorologist

noun  

person who studies patterns and changes in Earth's atmosphere.

millibar

noun  

(mbar) unit of pressure equal to .001 bar of atmospheric pressure.

oxygen

noun  

chemical element with the symbol O, whose gas form is 21% of the Earth's atmosphere.

precipitation

noun  

all forms in which water falls to Earth from the atmosphere.

scuba

noun, adjective  

(self-contained underwater breathing apparatus) portable device for breathing underwater.

sea level

noun  

base level for measuring elevations. Sea level is determined by measurements taken over a 19-year cycle.

weather

noun  

state of the atmosphere, including temperature, atmospheric pressure, wind, humidity, precipitation, and cloudiness.

wind

noun  

movement of air (from a high pressure zone to a low pressure zone) caused by the uneven heating of the Earth by the sun.

Long-term ethnic conflict in Ethiopia has been motivated by

A: Debate surrounding Egyptian access to the sources of the Nile River.

B: War with South Sudan.

C: Growth of terrorist cells in Somalia and Kenya.

D: Questions of state sovereignty.

E: Civil war with Eritrea.

Eyewitness: Weather
Name
Pd
1. The average temperature, winds, and rainfall that a place experiences over a period of years
make up its
2. The weather is what happens on a particular
3. In temperate regions, weather is (far more)
4. Weather vanes have been around since
ВС.
5. It is the
that drives our weather.
6.
keep the Earth warm after dark.
7. Has Niagra Falls ever frozen solid?
8. Virtually every society from the Japanese to the ancient Egyptians had some history of
worship.
which
9. The layer (of the atmosphere) nearest to us is the
actually is.
10. The troposphere is about
miles thick.
in the
11. Aristotle believed careful observation could reveal
12. Aristotle invented

which ocean is home to the tiny archipelago nation of comoros?

Use the passage to answer the question.

Which sustainability measures were implemented in the face of this crisis?

A.

preservation and conservation
B.

resource development and conservation
C.

resource development and preservation
D.

environmental protection and social equity
E.

environmental protection and economic growth

From the locations of past coastlines and possible future coastlines, what conclusion can be made about how sea level is tied to glacial growth

Which regions on Earth experience the greatest temperature change (and all the seasons)? Choose only one
Regions North of the Arctic Circle
Regions South of the Antarctic Circle
Regions between the Tropic of Cancer and Arctic Circle
Regions between the Tropic of Cancer and Tropic of Capricorn

All thunderstorms that form in the tropics eventually develop into tropical cyclones. Select one: True False

Why Neptune is the coldest planet​

What lies underneath volcanic features at earth's surface?.

the sedimentary layers above an erosive surface are __________ relative to all rocks present below the surface.

Which nations produce more of the world's pollution?

LDCS

MDCs

benefits of fitness of 16-year athletic individual

*
How are the words “rate”and “pattern”related and how are they different?'

Which of the following statements is true of environmental determinism?
O Most modern geographers follow this theory
It says that humans make appropriate choices about the environment they're in
O It suggests that people can adjust to the environment
the environment determines how societies develop in a particular area

reverse faults are created when plates push ________ each other.

We have already lost some 80 percent of the coral reefs in the Caribbean over the last three decades, and losses in the Pacific Ocean are also widespread. Reefs are like cities, with some parts growing and some parts being destroyed. When the net growth is positive, reefs can persist. Amazingly, coral reefs are threatened by such atmospheric conditions as

A) the growing hole in the ozone.
B) carbon dioxide emissions and global warming.
C) increases in UV radiation and the amount of reflected light.
D) increased particulate matter resulting in decreased UV rays.

Water pollution that occurs through the runoff, seepage, or falling of pollutants into the water is:

Can some please help me please I will give 30 points of answer is right and marked as brainliest also no links please

Which international organization would most likely defend a western European against an invasion from an Asian country?

A. The Red Cross
B. The World Health Organization
C. The Red Crescent
D. The North Atlantic Treaty Organization

Many settlers traveled west in covered wagons.TrueFalse

Define Explicit Cost .


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12. What is the purpose of government according to Locke? (1 point) O It was instituted to impartially settle disputes between individuals. O It attempted to save the sins of human nature through laws. O It was designed to keep men from acting like savages. O It was created to encourage self-preservation.​

¿por qué al trazar líneas paralelas al ecuador las regiones tienen los mismo biomas y en la misma distribución?

How did weathering help to shape the Appalachian Mountains?
O A. Weathering made the Appalachians tall and pointed by stripping
away the soil.
O B. Weathering rounded the mountains by breaking down jagged
peaks.
O C. Weathering created lakes in the mountain range by blocking the
flow of rivers.
O D. Weathering tilted the rocks under the surface by making tectonic
plates collide.
SURMIT

throughout the 3.5 billion year history of life on earth there has been a natural, low rate of species extinction known as

A rock that is especially rich in some commodity that is valuable is a mineral ; this rock is said to be , and the material that is desired in the rock is a(n) .

Is it possible to find gold in sedimentary rocks? If so, how? If not, why not?

Where does the intertropical convergence zone occur latitudinally on earths surface.

Which of the following is not one of Europe’s four major ethnic groups? A. Germanic B. Latin C. Basque D. Slavic Please select the best answer from the choices provided. A B C D.

T or F

1. Plains are never found along coastlines