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Title: GR8677.077
Post by: conantee on January 07, 2010, 09:30:50 PM
77. A particl is constrained to move along the x-axis under the influence of the net force \vec{F} = -k \vec{x} with amplitude A and frequency f, where k is a positive constant. When x = A/2, the particle's speed is
(A) 2 \pi f A
(B) \sqrt{3} \pi f A
(C) \sqrt{2} \pi f A
(D) \pi f A
(E)  \frac{1}{3} \pi f A