question_answer 42)

                  Give examples of a one-dimensional motion where                 (a) the particle moving along positive x-direction comes to rest periodically and moves forward.                 (b) the particle moving along positive moves backward.                

Answer:

                  \[f(t)=\sin t\] represents periodic motion of a particle                 (a) \[x(t)=t-\sin t\]                 (b) \[x(t)=\sin t\]