What is the amplitude of a particle executing uniform circular motion?

Study of which motion is required to understand many physical phenomena?

Which of the following functions of time represent $(a)$ periodic and $(b)$ non-periodic motion? Give the period for each case of periodic motion $[\omega$ is any positive constant].
$(i)$ $\sin \omega t + \cos \omega t$
$(ii)$ $\sin \omega t + \cos 2\omega t + \sin 4\omega t$
$(iii)$ $e^{-\omega t}$
$(iv)$ $\log(\omega t)$

Which one of the following is a simple harmonic motion?

Average velocity of a particle executing $SHM$ in one complete vibration is

For a particle showing motion under the force $F = -5(x - 2)$,the motion is ...........