The ________ theory offers a likely explanation for the formation of ________.
A. density wave; spiral arms
B. high rotation speed; spiral arms
C. density wave; Galactic bulge
D. high rotation speed; dark matter
Answer: A
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A 4.0-kg mass is placed at (3.0, 4.0) m, and a 7.0 kg-mass is placed at (3.0, -4.0) m. What is the moment of inertia of this system of masses about the z axis?
a. 275 kg•m2 c. 250 kg•m2 b. 90 kg•m2 d. 180 kg•m2
Suppose sand is leaking from an unpowered but moving railroad car. Since the sand is moving forward along with the car as it leaks out, it carries kinetic energy out of the car. This mass transfer will
A. Cause the car’s speed to increase. B. Cause the car’s speed to decrease. C. Have no effect on the car’s speed.
The visual appearance of Neptune is much bluer than Uranus
Indicate whether the statement is true or false
When I stand halfway between two speakers, with one on my left and one on my right, a musical note from the speakers gives me constructive interference. How far to my left should I move to obtain destructive interference? Select one:
a. one-fourth of a wavelength
c. one wavelength
b. half a wavelength
d. one and a half wavelengths