1.
Which of these aerodynamicists did not work on drag theories?
Correct Answer
C. Isaac Newton
Explanation
Isaac Newton is the only option among the given aerodynamicists who did not work on drag theories. While Newton made significant contributions to the field of physics, including the laws of motion and universal gravitation, his work did not specifically focus on drag theories in aerodynamics. On the other hand, Gustav Kirchhoff, Lord Rayleigh, and Jean de l'Ambert were all notable aerodynamicists who made contributions to the understanding of drag and other aspects of fluid dynamics.
2.
Who was the first person to predict the power needed for sustained flight?
Correct Answer
D. Charles Renard
Explanation
Charles Renard is credited with being the first person to predict the power needed for sustained flight. Renard, a French military engineer, conducted extensive experiments and calculations in the late 19th century to determine the necessary power requirements for a flying machine. His work laid the foundation for the development of aviation technology and helped pave the way for the Wright brothers and other pioneers of flight. Renard's predictions and insights were crucial in understanding the challenges and possibilities of powered flight.
3.
When was the power needed for sustained flights first predicted?
Correct Answer
A. 1889
Explanation
The power needed for sustained flights was first predicted in 1889.
4.
Who was the first person to become successful with glider flights?
Correct Answer
C. Otto Lilienthal
Explanation
Otto Lilienthal was the first person to become successful with glider flights. He was a German aviation pioneer who made significant contributions to the development of aviation. Lilienthal conducted extensive research and experiments on glider designs, ultimately achieving successful flights and making significant advancements in the field. His work and achievements laid the foundation for future developments in aviation and influenced many other aviation pioneers.
5.
When was the first powered airplane flown?
Correct Answer
A. 1903
Explanation
The first powered airplane was flown in 1903. This is a well-known fact in history as it marks the successful flight of the Wright brothers' aircraft, the Wright Flyer, in Kitty Hawk, North Carolina. This event is significant because it demonstrated the possibility of controlled, powered, and sustained flight, laying the foundation for modern aviation.
6.
Who flew the first powered airplane?
Correct Answer
B. Wright Brothers
Explanation
The Wright Brothers are credited with flying the first powered airplane. They successfully designed, built, and flew the Wright Flyer on December 17, 1903, in Kitty Hawk, North Carolina. Their historic achievement marked the beginning of modern aviation and revolutionized transportation and exploration. Lord Rayleigh was a British physicist who made significant contributions to the field of wave theory, but he did not fly the first powered airplane. Martin Kutta was a Czech mathematician and Otto Lilienthal was a German aviation pioneer, but neither of them flew the first powered airplane either.
7.
Who developed the mathematics behind thin-airfoil and lifting-line theories?
Correct Answer
B. Ludwig Prandtl
Explanation
Ludwig Prandtl developed the mathematics behind thin-airfoil and lifting-line theories. These theories are fundamental concepts in aerodynamics that explain the behavior of airfoils and the generation of lift. Prandtl's work revolutionized the understanding of aerodynamics and laid the foundation for modern aircraft design.
8.
Who was the first to investigate the properties of supersonic flow?
Correct Answer
A. Enst Mach
Explanation
Enst Mach was the first to investigate the properties of supersonic flow. He conducted extensive research and experiments on the behavior of gases at high speeds, particularly the phenomena of shock waves and the transition from subsonic to supersonic flow. Mach's work laid the foundation for the understanding of supersonic aerodynamics and had a significant impact on the development of supersonic aircraft.
9.
What is the ratio of the flow speed to the speed of sound called?
Correct Answer
B. Mach number
Explanation
The ratio of the flow speed to the speed of sound is called the Mach number. It is named after the Austrian physicist and philosopher Ernst Mach, who made significant contributions to the understanding of shock waves. The Mach number is used to describe the speed of an object or fluid in relation to the speed of sound in that medium. A Mach number less than 1 indicates subsonic flow, while a Mach number greater than 1 indicates supersonic flow.
10.
Which of these is not a conservation law of fluid mechanics?
Correct Answer
D. Conservation of momentum
Explanation
The conservation of momentum is not a conservation law of fluid mechanics because momentum can be transferred between fluid particles through forces such as pressure and viscous forces. In other words, the total momentum of a fluid system can change due to external forces acting on it. On the other hand, the conservation of mass, energy, and force are all fundamental principles in fluid mechanics that state that mass, energy, and force are conserved within a closed system.