How do we learn about the conditions at the center of our own galaxy, the Milky Way?
A) The gas and dust in the Milky Way prevent any type of direct observation of the galactic center, but theoretical models allow us to predict what is happening there.
B) We must look at the centers of other (external) galaxies and assume that they are similar to the Milky Way.
C) While we cannot see the galactic center with visible or ultraviolet light, radio and X-rays from the center can be detected and used to determine the conditions there.
D) High-resolution photographs obtained by the Hubble Space Telescope have revealed the galactic center using visible light.
C
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A solid cylinder of radius R = 1.0 m and mass 10 kg rotates about its axis. When its angular velocity is 10 rad/s, its angular momentum (in kg?m2/s) is
A. 50. B. 20. C. 40. D. 25. E. 70.
After one _______________. of 18 years 11 1/3 days, the pattern of eclipses repeats
Fill in the blank(s) with correct word
An object is thrown vertically and accelerates downward at +9.80 m/s2 (downward is positive and upward is negative)
(a) What is its displacement after 5.00 s if it starts at 2.50 m/s? (b) How fast is it moving after that 5.00 s?
Two long parallel wires carry currents of 20 A and 5.0 A in opposite directions. The wires are separated by 0.20 m. What is the magnitude of the magnetic field midway between the two wires? (?0 = 4? × 10-7 T • m/
A) A) 1.0 × 10-5 T B) 2.0 × 10-5 T C) 3.0 × 10-5 T D) 4.0 × 10-5 T E) 5.0 × 10-5 T