question_answer 27)

                  The displacement of a particle is represented by the equation \[y={{\sin }^{3}}\,\omega t\]. The motion is                 (a) non-periodic.                 (b) periodic but not simple harmonic.                 (c) simple harmonic with period \[2\pi /\omega \]                 (d) simple harmonic with period \[\pi /\omega \]

Answer:

                  (b) In this case, acceleration is not proportional to the displacement.