You already have the following notes on a handout.
Properties of Air: Student Notes
· Air is matter; it is made of atoms and molecules
· Since air is matter it has mass and weight
o A balloon full of air weighs more than an empty balloon
o Gravity acts on each molecule of gas pulling it down to earth
· Air has pressure
o A ruler under a large piece of newspaper can’t easily raise a newspaper off a table because of the air pressure above the newspaper
o Blowing air between 2 suspended ping pong balls makes them bounce together instead of flying apart because the faster moving air has less pressure than the slower moving air
o When a straw is placed in water and your thumb is placed on top of the top end, and then the straw is removed, the water stays in the straw because the air pressure below the straw holds it up
· Bernoulli’s Principle: A rise in pressure must always be accompanied by a decrease in the speed or an increase in the speed results in a decrease in the pressure; OR simply fast moving air exerts less pressure than slow moving air.
o When a straw is in the water and air is blown across the opening of the straw, water travels up the straw. This happens because the fast moving air above the straw has less pressure and the atmospheric pressure (which is higher pressure) is pushing water up the straw
· Warm air expands and cold air contracts
o When a full balloon is taken outside on a cool day, its particles move slower and take up less space so it shrinks.
o When that same balloon is taken inside, the particles move faster and take up more space so it becomes full once more
· Warm air rises and cool air sinks
o As air warms, it expands. When air expands, it takes up more space and its density decreases. Less dense air rises over more dense air.
o As air cools, it contracts. When air contracts, it takes up less space and its density increases. More dense air sinks under less dense air.
The following terms can be found on your handouts as well.
Newton's Third Law
Coanda Effect
Bernouillis principle
Angle of Attack
Aerodynamic Lift
Law of Flight
Airfoil
The Four Forces of Flight
- Lift
- Drag
- Gravity/Weight
- Thrust
History of Air and Space Travel: Study the timeline from your package. The website I used to add dates to the timeline is:
http://www.loc.gov/exhibits/treasures/wb-timeline.html
