What type of object is believed to be the central source of energy for an active galaxy?
A. globular cluster
B. a large amount of gas and dust
C. an unusually large and bright main sequence star
D. a massive black hole
Answer: D
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Exhibit 12-2
The figure below shows a graph of angular velocity versus time for a man bicycling around a circular track.
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Use this exhibit to answer the following question(s).
Refer to Exhibit 12-2. What is his average angular acceleration, in rad/s2, in the period from t = 6 min to t = 8 min?
A.
B.
C.
D.
E.
The energy of a photon depends on
A) its amplitude. B) its velocity. C) its frequency.
Rank the following five capacitors in the order of the magnitudes of the charges on their plates
(a) a 20-µF capacitor with a 4-V potential difference between its plates (b) a 30-µF capacitor with charges of magnitude 90 µC on each plate (c) a capacitor with charges of magnitude 80 µC on its plates, differing by 2 V in potential, (d) a 10-µF capacitor storing energy 125 µJ (e) a capacitor storing energy 250 µJ with a 10-V potential difference
1.e > a > b > d > c 2.e > d > a > b > c 3.c > b > a > d > e 4.b > a = c > d = eMost of the detailed information about the planets in our solar system comes from
A) telescopic observations from Earth B) robotic spacecraft C) human visits D) meteorites