[DOC] [TLE] Heat Rises...and Falls  Stack Effect, Air Movement, & Heat Flow [PAR] Jan 30, 2012 ... The stack effect can be huge in winter and allow a lot of warm air to escape ... 
Your observation that in the warm months convection currents can draw ... One in 
particular is when the statement "warm air rises" is followed with... [DOC] [TLE] Why can warm air hold more moisture than ... - Little Shop of Physics [PAR] Reach for the sky. Why can warm air hold more moisture than cold air? ... phase
, so there will be more water vapor in the air. This activity is a good one for ... their 
dice a few more times, so they can observe people switching from one side. [DOC] [TLE] Air Pressure Can Crusher - SICK Science - The Lab [PAR] Using one swift motion, lift the can off the burner, turn it upside down, and plunge 
it ... Each time you repeat the experiment, carefully observe what is happening in 
order to ... Electric Stove or hot plate; Cooking tongs; Gloves; Bowl; Cold water... [DOC] [TLE] Temperature Changes Everything - Science NetLinks [PAR] One of the most important concepts for students to understand is that ... As the air 
contained inside the balloon begins to warm, the molecules begin to strike the ... 
Here they will see how the characteristics of solids, liquids, and gases can be 
explained by particle motion. ... What did you observe inside the bottle as it 
cooled? [DOC] [TLE] Observation - nikkemedia.fi [PAR] Which one can rise higher, a toy balloon or a hot air balloon? Observation. In the 
Science Centre Heureka there is a hot air balloon available for observation. [DOC] [TLE] The Observation of Air Temperature in the Tropics - JStor [PAR] rare; more often the situation is nearly as bad as it can be; often, again, one may 
expect very good ... yS tion, so that the hot air is imprisoned. + z ^^^^^^~ vjust... [DOC] [TLE] Grades 12: Physical Science: Section Resources - Education Place [PAR] Section 2: Hot Air, Cold Air: Students conduct experiments to see that air ... 
Students then observe how air pressure can hold water in a straw and in an 
inverted ... and how differences in air pressure can push objects from one place 
to another. [DOC] [TLE] Air, It's Really There | Chapter 1: MatterSolids, Liquids, and Gases ... [PAR] In a gas, the molecules have very weak attractions for one another. ... The inflated 
ball has the greater mass so students can conclude that gas is matter because ... 
They dip the mouth of a bottle in detergent solution and observe a bubble ... 2 
clear plastic cups; 8-oz plastic bottle; Detergent solution in a cup; Hot water (
about... [DOC] [TLE] How Does a Hot Air Balloon Fly? | Wonderopolis [PAR] One cubic foot of air inside the envelope can lift about seven grams, which is only 
a tiny amount of weight. This is why hot air balloons have to be so massive. [DOC] [TLE] Balloon (aeronautics) - Wikipedia [PAR] In aeronautics, a balloon is an unpowered aerostat, which remains aloft or floats 
due to its .... The lower one held hot air and could be quickly heated or cooled to 
provide the varying lift for good altitude control. .... The French military 
observation balloon L'Intrpide of 1795 is the oldest preserved aircraft in Europe; 
it is on... [DOC] [TLE] First World War.com - Encyclopedia - Observation Balloons [PAR] Gas or hot-air propelled, such balloons were by no means a new innovation in 
terms ... accompanied by one or two others for comparative observation purposes
. ... balloon and unless the attacking aircraft could succeed in setting the balloon
... [DOC] [TLE] NWS JetStream - Air Pressure [PAR] Air pressure can be increased (or decreased) one of two ways. ... observation 
stations around the world the air pressure reading, regardless of the observation 
station elevation, ... In very hot weather, the fall of the barometer denotes thunder. [DOC] [TLE] Severe Weather 101: Tornado FAQ [PAR] Tornadoes need moisture and warm air to form, which is

Question: One can be observation or hot-air
Answer: balloon