Module 8 air pressure

Question 1

What is atmospheric pressure?

Answer 1

The force applied for a particular unit area, calculated as P = F/A.

Question 2

What is the atmospheric pressure at sea level in PSI?

Answer 2

14.7 pounds per square inch (PSI).

Question 3

What is the atmospheric pressure at sea level in metric units?

Answer 3

1.03 kg for every square centimeter.

Question 4

At what altitude do most commercial airplanes fly?

Answer 4

30,000 to 40,000 feet above sea level.

Question 5

What medical condition can occur at high altitudes due to thin air?

Answer 5

Hypoxia.

Question 6

What are the symptoms of hypoxia?

Answer 6

• Shortness of breath
• Confusion
• Possible loss of consciousness.

Question 7

Why are airplane cabins pressurized?

Answer 7

To mimic sea level’s atmospheric pressure of 14.7 PSI.

Question 8

What physiological adjustment occurs in the ears due to altitude changes?

Answer 8

Ears may ‘pop’ due to pressure equalization via the Eustachian tube.

Question 9

What happens to gases in the body if placed in an area of drastically lower pressure?

Answer 9

Gases like nitrogen would expand and form bubbles that could block vessels or destroy cells.

Question 10

How does the body adapt to high altitudes over time?

Answer 10

By increasing the number of red blood cells to carry oxygen more efficiently.

Question 11

What instrument is used to measure air pressure?

Answer 11

Barometer.

Question 12

What is a mercury barometer?

Answer 12

A barometer that uses mercury in a tall tube to measure air pressure.

Question 13

What is the average barometric pressure at sea level in millimeters of mercury?

Answer 13

760 mmHg.

Question 14

What is an aneroid barometer?

Answer 14

A type of barometer that records changes in pressure on paper or a scale.

Question 15

How many millibars are in one atmosphere at sea level?

Answer 15

1013.25 mbar.

Question 16

What is the Pascal in relation to atmospheric pressure?

Answer 16

There are 101,325 Pa in one atmosphere.

Question 17

What adjustments do meteorologists make when recording air pressure?

Answer 17

Adjustments for different elevations to report a standard sea-level air pressure.

Question 18

What is an isoline that connects points of equal atmospheric pressure called?

Answer 18

Isobar.

Question 19

What indicates a high-pressure center in isobars?

Answer 19

Isobars increase in value as they move toward the center.

Question 20

What indicates a low-pressure center in isobars?

Answer 20

Isobars decrease in value as they move toward the center.

Question 21

What factors affect air pressure?

Answer 21

• Temperature
• Altitude
• Water vapor.

Question 22

What happens to air pressure as temperature increases at sea level?

Answer 22

Air pressure decreases due to the expansion of air.

Question 23

What happens to air pressure as altitude increases?

Answer 23

Air pressure decreases.

Question 24

How does humidity affect air density and pressure?

Answer 24

Increased water vapor decreases air density and pressure.

Question 25

What is the effect of gravity on atmospheric pressure at higher altitudes?

Answer 25

Air expands due to decreased force of gravity.

Question 26

What is the atmospheric pressure at about 18,000 feet elevation?

Answer 26

0.5 atmospheres of pressure.

Question 27

What is the relationship between humidity and air density?

Answer 27

Moist air is lighter than dry air, causing lower density.

Question 28

Fill in the blank: The average barometric pressure at sea level is _______.

Answer 28

29.92 inches Hg.

Question 29

True or False: High-pressure areas typically indicate stormy weather.

Answer 29

False.