Understanding Atmospheric Pressure

What causes dust particles to move randomly in a ray of sunlight?

• Static electricity in the air

• The Earth's magnetic field

• Constant collisions with gas particles

• Heat from the sunlight

What is atmospheric pressure?

• The weight of water vapour in the air

• The force of the wind against objects

• The pressure exerted by gas particles colliding with objects

• The temperature of the atmosphere

How do meteorologists typically measure atmospheric pressure?

• With a thermometer

• With a barometer

• With an anemometer

• With a hygrometer

What is one atmosphere (atm) equal to at sea level?

• 1,013 millibars

• 500 millibars

• 2,026 millibars

• 100 millibars

What type of weather system usually brings cloudiness and precipitation?

• High-pressure system

• Low-pressure system

• Normal pressure system

• Variable pressure system

Why is air pressure lower at higher altitudes?

• Because the temperature is always higher

• Because there are fewer gas particles colliding

• Because gravity is stronger

• Because wind speeds are faster

Compared to sea level, what is the atmospheric pressure on Mount Everest?

• About two-thirds of sea level pressure

• The same as sea level pressure

• About one-third of sea level pressure

• Double the sea level pressure

What happens to available oxygen as altitude increases?

• It increases

• It stays the same

• It decreases

• It becomes more concentrated

Why do mountain climbers use bottled oxygen at high altitudes?

• To prevent altitude sickness

• To stay warm

• To increase climbing speed

• To improve visibility

What causes decompression sickness?

• Extremely high temperatures

• Moving too quickly between pressure differences

• Lack of water

• Strong winds