Of the various wavelengths emitted from a hydrogen gas discharge tube, those associated with transitions from higher levels down to the n = 2 level produce which of the following?
a. visible
c. ultraviolet
b. infrared
d. a mixture of visible and ultraviolet
D
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What is the Kuiper Belt?
A. an enormous aggregate of gas and dust from which the Solar System was formed B. a large belt containing asteroids in a gap between the orbits of Mars and Jupiter C. a swarm of comet nuclei in a huge shell surrounding the Sun and planets D. a disklike swarm of icy objects that lies from near the orbit of Neptune to past Pluto's orbit
The gravitational red shift is caused by
A) gravitational lensing. B) rotating black holes. C) time dilation. D) Rayleigh scattering in the atmosphere.
Develop a reasonable layout of nodes and control volumes for the geometry shown in the sketch. Provide a scale drawing showing the problem geometry overlaid with the nodes and control volumes.
GIVEN Two-dimensional transient conduction at an inside corner with specified-flux boundary condition FIND (a) The control volume energy balance equation,
Starship "Alpha" is traveling at 0.8c (? = 5/3) with respect to the identical starship "Beta." Each starship has rest length 10,000 m. The ship's engineer aboard the "Beta" measures the length of the "Alpha" as it passes by his window. What result should he get?
A. 10,000 m B. 16,667 m C. 12,500 m D. 6,000 m E. 8,000 m