Basic aerodynamics

#7. In accordance with the principle of continuity: 1. air accelerates when the cross-sectional area of a streamline flow is reduced. 2. when air accelerates the density of air in a streamline flow is increased. 3. air decelerates when the cross-sectional area of a streamline flow is increased. 4. changes in cross-sectional area of a streamline flow will affect the air velocity. Which of the preceding statements are true?

• A1, 2, 3 and 4.
• B1 and 4
• C3 and 4.
• D1, 3 and 4.

#11. The statement, "Energy and mass can neither be created nor destroyed, only changed from one form to another", refers to:

• ABernoulli's theorem
• BThe equation of kinetic energy
• CThe principle of continuity
• DBernoulli's principle of continuity

#8. In accordance with the principle of continuity:

• AAir accelerates when the cross-sectional area of a streamline flow is reduced
• BWhen air accelerates the density of air in a streamline flow is increased
• CAir decelerates when the cross-sectional area of a streamline flow is increased
• DChanges in cross-sectional area of a streamline flow will affect the air celocity