Two simple harmonic motions are given by `y_(1) = a sin [((pi)/(2))t + phi]` and `y_(2) = b sin [((2pi)/( 3))t + phi]`. The phase difference between these after `1 s` is

Explanation

At t = 1 sec
`y_(1) = a sin ((pi)/(2) + phi), " "y_(2) = b sin ((2pi)/(3)+phi)`
Hence phase difference is `((2pi)/(3)+phi)-((pi)/(2)+phi) = (pi)/(6)`