NASA uses the famous "Vomit Comet," a KC-135 cargo plane, to provide astronauts and scientiest a simulated zero-gravity environment. The plane flies in a parabolic arc, at the top of which a passenger feels "weightless." This is because
A. the acceleration of the passenger is nearly zero at the top of the arc
B. the gravitational force exerted by Earth on the passenger is nearly zero at the top of the arc
C. the force exerted by the floor of the plane on the passenger is nearly zero at the top of the arc
D. a and b
Answer: C. the force exerted by the floor of the plane on the passenger is nearly zero at the top of the arc
You might also like to view...
Motional Emf: An electromagnetic flowmeter is useful when it is desirable not to interrupt the system in which the fluid is flowing (such as the blood in an artery during heart surgery). Such a device is illustrated in the figure. The conducting fluid moves with speed v in a tube of diameter d. Perpendicular to this tube is a magnetic field B. A voltage V is induced between opposite sides of the tube due to the motion of the conducting fluid in the magnetic field. For a certain case, B = 0.120 T, d = 1.2 cm, and the measured voltage is 10-3 = 2.88 mV. Determine the speed of the fluid. 
A. 2.0 m/s B. 11 m/s C. 0.075 m/s D. 1.1 m/s E. 750 m/s
During various stages of evolution, low mass stars (like the Sun) differ significantly from high mass stars. How do they differ in terms of observational properties while Main Sequence stars?
What will be an ideal response?
Process of Science: Why is String Theory not really a theory?
What will be an ideal response?
Which of the following describes the light that can be detected from a person?
A) The person reflects many wavelengths of visible light and emits infrared light. B) The person emits many wavelengths of visible light and reflects infrared light. C) The person emits a few narrow wavelengths of visible light based on the elements that make up the human body. D) The person reflects a few narrow wavelengths of visible light based on the elements that make up the human body.