Lecture Notes: Principles of Flight

1. Properties of Air

• Air has mass: This means air has weight.
• Air takes up space: It's present everywhere around us.
• Air exerts pressure: It applies force on objects.
• Air is compressible: It can be condensed into a smaller volume.
• Importance: These properties are crucial for enabling flight.

2. The Four Forces of Flight

• Lift
  • Direction: Upward
  • Function: Pushes the object upwards, counteracting gravity.
• Weight
  • Direction: Downward
  • Function: The gravitational pull on the object.
• Thrust
  • Direction: Forward
  • Function: Moves the object forward.
• Drag
  • Direction: Backward
  • Function: Air resistance that decelerates the object.
• Balanced Forces: Achieving a balance among these forces results in smooth and level flight.

3. Bernoulli’s Principle

• Fast-moving air: Results in low pressure.
• Slow-moving air: Results in high pressure.
• Application to Flight:
  • Airplane wings are designed to be curved on top.
  • This design causes air to move faster over the top of the wings, creating lower pressure above.
  • Higher pressure underneath the wings generates lift, allowing the plane to rise.