Science Air Pressure 5.2 And 5.3 Flashcards
What is air pressure?
The force caused by air pushing down on an object; air pressure is exerted in all directions.
What is density?
How close molecules are to each other, the mass per unit volume of a substance.
What is a barometer?
An instrument used to measure air pressure.
What is an aneroid barometer.
A type of barometer that does not contain liquid.
What is a millibar?
Unit of air pressure shown on weather maps
What is a high-pressure system?
Cooler denser, sinking, air that usually produces clear skies and fair weather.
What causes air pressure? Explain.
Warmer, less dense rising
How does a barometer measure air pressure?
A glass tube closed at one end is filled with mercury.
How is a barometer used to predict the weather?
A barometer can measure air pressure and then air pressure has high or low pressure systems.
What are is the difference of cold air vs warm air?
Cold air is more dense and it falls down and hot air is less dense and it rises.
What are isobars?
The air pressure lines on weather maps.
Explain how air pressure can help Boeing 747 fly?
When a plane goes lower, there is more air pressure. If they go higher, there is less air pressure.
What happens when you place a barometer in sunlight?
If a mercury barometer is in sunlight it might have a change in the mercury.
What is altitude?
How high something goes.
What is the source of energy that sets Earth’s atmosphere in motion and causes weather changes.
The sun.
The weight of air is indicated by what in a mercury barometer?
The height of the mercury column in the glass tube.
What does a rising barometer usually indicate? What kind of pressure system and what kind of weather.
An approaching high pressure system and fair weather.
How do winds form?
Warm air rises and then cool air replaces the hot air making a breeze.
What is wind?l
The horizontal movement of air over earth’s surface
What is sea breeze?
A cool wind that blows onshore in daytime.
What is land breeze?
A warm breeze that blows offshore at night .
What is prevailing westerlies?
A wind belt in the lower atmosphere where winds blow from from the southwest, generally between 30-60 degrees latitude.
What is wind chill index?
The temperature we receive due to the effects of wind.
What is the difference between land and sea breezes?
Land breezes are on land and they are much hotter. Sea breezes are on the sea and they are much colder.
