Approximately how many comets are thought to be in the Oort cloud?
A) a thousand
B) a million
C) a billion
D) a trillion
E) a quintillion
D) a trillion
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Two capacitors with capacitances of 2.0 ?F and 0.40 ?F, respectively, are connected in series. The system is connected to a 50-V battery. What electrical potential energy is stored in the 2.0-?F capacitor?
a. 2.5E–3 J b. 5.0E–4 J c. 8.3E–5 J d. 6.9E–5 J e. 1.4E–5 J
The relationship 
for an elliptical orbit follows from the fact that the satellite’s velocity is perpendicular to its position vector at the two extreme points and also from
A. Conservation of angular momentum. B. Conservation of energy. C. Conservation of momentum. D. Newton’s second law. E. Some other properties of ellipses. F. (The given relationship is false!)
Consider two planets in space that gravitationally attract each other. If the masses of both planets are doubled, and the distance between them doesn't change, then the force between them is
A) one-quarter. B) half as much. C) twice as much. D) four times as much. E) none of the above
Radioactivity Basics: Suppose that starting with 
, the following sequence of decays occurs: first an alpha decay, then a beta-minus decay, and finally another alpha decay. What isotope is left after each one of the decays?
What will be an ideal response?