Which two classes of objects were critical to the Shapley-Curtiss Debate of 1920?
A) white dwarfs and red giants
B) open clusters and emission nebulae
C) globular clusters and spiral nebulae
D) emission nebulae and spiral nebulae
E) planetary nebulae and white dwarfs
C
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Whirl a rock at the end of a string and it follows a circular path. If the string breaks, the rock tends at first to
A) continue in a circular path. B) follow a straight-line path. C) spiral inward. D) fall straight downward.
Which of these wins the prize as the blandest appearing planet as revealed visually by space probes?
a. Jupiter b. Saturn c. Uranus d. Neptune
A 3.0-cm tall statue is 48 cm in front of a convex lens having a focal length of magnitude 20 cm
(a) Is the image of the statue real or virtual? (b) How far is the image from the lens? (c) Is the image upright or inverted? (d) How tall is the image?
A resistor and a capacitor are connected in series to an ideal battery of constant terminal voltage. At the moment contact is made with the battery, the voltage across the capacitor is
A) greater than the battery's terminal voltage. B) equal to the battery's terminal voltage. C) less than the battery's terminal voltage, but greater than zero. D) zero.