What evidence tells us that quasars are the centers of distant galaxies?
A) Rapid variations in quasar luminosity tell us that they must be quite small in size.
B) Quasars are extremely luminous.
C) All quasars have large redshifts.
D) Images and spectra show quasars to be embedded at the centers of distant galaxies.
D
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Thin Lenses: A coin is 12 cm in front of a converging lens with focal length of magnitude 4.0 cm. Where is the image?
A. 8.0 cm behind the lens B. 6.0 cm in front of the lens C. 6.0 cm behind the lens D. 4.0 cm in front of the lens
A 1024 Hz tuning fork is dangled at the end of a string such that its center of mass is 1.2 m below the point at which the other end of the string is attached to door frame, making a pendulum of sorts. The tuning fork may be treated as a point mass for the purposes of this problem. If the pendulum is brought to a maximum angle and released. If the range of frequencies heard by an observer standing in the plane of the pendulum's motion is 1020-1028 Hz, what is the angle to which the pendulum was raised? The speed of sound in this case is 340 m/s.
a. 
b. 
c. 
d. 
e. 
If the lifetime of a particle is roughly inversely proportional to the relative strength of the force involved, then for the strong, electromagnetic, and weak forces, arrange the forces according to their resulting lifetimes ranging from shortest to longest lifetimes
a. strong, electromagnetic, weak b. weak, electromagnetic, strong c. weak, strong, electromagnetic d. strong, weak, electromagnetic
The radius of the Sun is 6.95 × 108 m. It radiates heat at the rate of 5.42 × 1026 W. Assuming that it is a perfect emitter, what is the temperature of the surface of the Sun? The Stefan-Boltzmann constant is 5.67 × 10-8 W/(m2?K4)
A) 6.30 × 103 K B) 8.25 × 103 K C) 8.87 × 103 K D) 3.93 × 107 K E) 5.78 × 107 K