Chapter 14: Gases Flashcards
About what percentage of the molecules that make up the atmosphere are below an aircraft that flies at an altitude of 6 kilometers: 30%, 50%, more than 50%, 40% or 20%?
more than 50%
What is the approximate mass of a 1-square-centimeter column of air that extends from sea level to the top of the atmosphere?
1 kilogram
A balloon is buoyed up with a force equal to the
weight of air it displaces.
A bubble of air released from the bottom of a lake
becomes larger as it rises
If water flows into a smaller diameter pipe and speeds up, the bubbles in the water
expand.
As a helium-filled balloon rises in the air, it becomes
less dense
The most common state of matter in the universe is
plasma.
A one-ton blimp hovers in the air. The buoyant force acting on it is
one ton.
In drinking soda or water through a straw, we make use of
atmospheric pressure.
If you are standing in a cave on a cliff, and the air outside the cave is moving much faster than the air inside the cave,
the pressure difference wants to push you out of the cave.
Atmospheric pressure (def)
The pressure exerted against bodies immersed in the atmosphere. It results from the weight of air pressing down from above. At sea level, atmospheric pressure is about 101 kPa.
Barometer (def)
Any device that measures atmospheric pressure.
Boyle’s law
The product of pressure and volume is a constant for a given mass of confined gas, as long as temperature remains unchanged: P1V1 = P2V2
Archimedes’ principle (for air)
An object in the air is buoyed up with a force equal to the weight of displaced air.
Bernoulli’s principle
When the speed of a fluid increases, internal pressure in the fluid decreases.
