Based on inventoried matter in the universe, including dark matter known to exist in galaxies and clusters, the actual density of the universe is what fraction of the critical density?
A) 1 percent
B) 10 percent
C) 26 percent
D) 74 percent
E) 100 percent
C
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Four people are sitting at the lettered positions on the rim of a merry-go-round shown below that is slowly turning clockwise. You throw a fairly massive ball horizontally to one of these people, who catches it. To which person should you throw the ball so that catching it most effectively increases the merry-go-round’s rotation rate? 
A. A B. B C. C D. D
You observe the same spectral line in two stars that are identical in every way except that one rotates faster than the other. How does the spectral line differ between the two?
A) There is no difference. B) The line in the faster rotating star is blueshifted. C) The line in the faster rotating star is redshifted. D) The line in the faster rotating star is broader. E) The line in the faster rotating star is narrower.
An object of unknown weight is suspended as shown. The tension in rope 1 is 25 lb, and the tension in rope 2 is 31 lb. What is the weight of the suspended object?
A. 36 lb B. 33 lb C. 41 lb D. 39 lb E. 56 lb
The unit of work is:
a. the newton. b. the meter. c. the slug. d. the hour. e. the joule.