Light travels fastest in
A) warm air.
B) cool air.
C) a vacuum.
Answer: C
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A 200-? resistor, a 40.0-mH inductor and a 2.00-?F capacitor are connected in series with a 120-V rms source at 1000 Hz. What is the impedance of this circuit?
A) 164 ? B) 120 ? C) 264 ? D) 200 ? E) 364 ?
When a planet moves closer to the Sun in an elliptical orbit, its rotational inertia about the sun
A. gets smaller because its distance from the Sun is smaller. B. gets larger because the angular momentum must be conserved. C. gets smaller because the lever arm is shorter. D. gets larger because the planet has more angular acceleration. E. does not change because the mass of the planet is constant.
Several electrons are placed on a hollow conducting sphere. They
A) clump together on the sphere's outer surface. B) clump together on the sphere's inner surface. C) become uniformly distributed on the sphere's outer surface. D) become uniformly distributed on the sphere's inner surface. E) become randomly distributed on the shere's outer and inner surfaces.
Which would you expect to be more viscous, a polymer made of long molecular strands or one made of short molecular strands? Why?
A) short molecular strands because of a greater density B) long molecular strands because they tend to tangle among themselves C) short molecular strands because their ends are typically polar D) long molecular strands because of a greater molecular mass