Physics Chapter 20 Flashcards

Earth's Atmosphere

• The atmosphere is composed of various molecules that extend many kilometers above the Earth's surface.
• It plays a crucial role in supporting life and influencing weather patterns.

Atmospheric Pressure

• Caused by the weight of air, similar to how water pressure results from the weight of water.
• Measured using various instruments to understand its effects on weather and flight.

Barometer Types

• Barometer: An instrument designed to measure atmospheric pressure.
• Mercury Barometer: Uses mercury in a tube; the height of the mercury indicates atmospheric pressure.
• Aneroid Barometer: Measures pressure changes using a flexible metal box that responds to variations in air pressure.

Boyle's Law

• States the product of pressure and volume remains constant for a given mass of gas when temperature is held steady.
• Key principle used in understanding gas behavior under varying pressure conditions.

Buoyancy

• An object will rise if it is less dense than the surrounding air, demonstrating principles of buoyancy.

Bernoulli's Principle

• Highlights that an increase in fluid speed results in a decrease in fluid pressure, essential in understanding how lift is generated.

Fluid Dynamics

• Streamlines: Represent the smooth path of fluid motion in a steady flow, crucial for visualizing fluid behavior.
• Eddies: Defined as turbulent, changing paths in fluid flow, showcasing complex fluid dynamics.

Lift and Flight

• Lift is the upward force resulting from the pressure difference between the air above and below a wing.
• Horizontal flight is achievable when lift balances with the weight of the aircraft, enabling stable flight.