Lecture 2 Flashcards
What makes up the atmosphere?
78% Nitrogen
21% Oxygen
1% Other
By _____ feet, half of all the air on the planet is below you and by ____ feet, 75% of all air is below you.
18,000
34,000
How does temperature affect the density of air?
Air expands when heated
Air is less dense when it is ____ and more dense when it is ____.
hot
cold
How does humidity affect the density of air?
Water vapor is less dense than air (less dense in high humidity)
Air is less dense when there is ____ humidity and more dense when there is ____ humidity.
high
low
How does altitude affect the density of air?
Fewer air molecules as you reach higher altitude
Air molecules can spread out more at higher altitudes
Air is less dense at ____ altitude and more dense at ____ altitude.
high
low
Air is least dense on ____, ____ days, and at ____ altitude.
Air is most dense on _____, _____ days and near _____.
hot
humid
high
cool
dry
sea level
What is a standard day?
59°F
Sea level
Zero humidity
What are the four forces on an airplane?
Lift
Weight
Thrust
Drag
What is Newton’s 1st Law?
Which force(s) does it apply to?
A body at rest will stay at rest until an external force acts on it
Drag
What is Newton’s 2nd Law?
A force applied to an object at rest causes it to accelerate in the direction of the force
What is Newton’s 3rd Law?
Which force(s) does it apply to?
For every action, there is an equal and opposite reaction
Accounts for 10% of lift
Thrust
What is Bernoulli’s Principle?
As the velocity of a fluid increases, the pressure decreases
