High Speed Airflow Quiz

What is the speed of sound in air at 15 °C at sea level?

• 300 m/s

• 340 m/s

• 350 m/s

• 400 m/s

Which aircraft was the first to break the sound barrier?

• Concorde

• Bell X-1

• Tupolev Tu-144

• SR-71 Blackbird

What is the Mach number when an aircraft is traveling at the speed of sound?

• M = 0

• M = 1

• M = 2

• M = 0.5

What phenomenon occurs when an aircraft approaches the speed of sound?

• Drag

• Lift

• Turbulence

• Shock wave

What is the critical Mach number?

• The speed at which airflow first reaches Mach 1

• The speed of sound

• The speed of an aircraft in subsonic flight

• The speed of an aircraft in supersonic flight

What is compressibility buffeting?

• Loss of control surface efficiency

• Increased drag at subsonic speeds

• Localized airflow reaching Mach 1

• Smooth airflow over wings

What is aerodynamic heating?

• Increase in lift due to speed

• Cooling of aircraft surfaces

• Conversion of kinetic energy into heat energy

• Reduction of drag at high speeds

What does the area rule state?

• Aircraft must be symmetrical

• Wings must be straight for optimal performance

• Cross-section must vary regularly to minimize drag

• Engines should be placed at the rear

What is the effect of sweepback on critical Mach number?

• Has no effect

• Decreases the critical Mach number

• Makes the aircraft heavier

• Increases the critical Mach number

What is a normal shock wave?

• Occurs only at subsonic speeds

• Is a type of turbulence

• Is created by low-speed aircraft

• Forms perpendicular to the airstream