Stars within a cluster that are at the turnoff point
a. have life expectancies that are equal to the age of the cluster.
b. are stars that are just becoming white dwarfs.
c. are stars that are just entering the main sequence portion of their evolution.
d. are stars that are about to supernova.
e. are stars that are generally spectral type G stars.
a
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Suppose the angular separation of two stars is smaller than the angular resolution of your eyes. How will the stars appear to your eyes?
A) You will not be able to see these two stars at all. B) The two stars will look like a single point of light. C) The two stars will appear to be touching, looking rather like a small dumbbell. D) You will see two distinct stars. E) You will see only the larger of the two stars, not the smaller one.
Suppose that at a certain instant of time, the wave function shown below describes a certain quanton’s state. If we were to perform an experiment to locate the quanton, what would be the least likely result or results within the graph’s range? 
A. 
B. 
C. 
D. 
In the double-slit experiment with electrons, suppose that the observer uses a detector to determine through which slit the electron actually passes. Does this affect the outcome of the experiment, and why or why not?
A) No, the pattern on the screen remains an interference pattern, regardless of the detector. B) No, the pattern on the screen remains a non-interference pattern, regardless of the detector. C) Yes, the detector causes the pattern on the screen to suddenly change from an interference pattern [with no detector] to two tiny spots directly behind each slit [with the detector]. D) Yes, the detector causes the pattern on the screen to suddenly change from an interference pattern [with no detector] to a non-interference pattern [with the detector]. E) Yes, the detector causes the pattern on the screen to suddenly change from a non-interference pattern [with no detector] to an interference pattern [with the detector].
The water behind Grand Coulee Dam is 1200 m wide and 160 m deep. Find the hydrostatic force on the back of the dam. (Hint: the total force = average pressure × area)
a. 5.2 × 10^9 N c. 13.2 × 10^10 N b. 8.8 × 10^10 N d. 15.1 × 10^10 N