41. A 2.0 kg particle moves along an x axis, being pushed by a variable force directed along that axis. Its position is given by
. What is the force on the particle at t = 2.0 s ?
(A)
(B) 
(C) 
(D) 
(E) 
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統計: A(0), B(3), C(1), D(46), E(1) #2020485
統計: A(0), B(3), C(1), D(46), E(1) #2020485