Two identical pendulums are connected by a light coupling spring. Each pendulum has a length $$ of $0\mathrm{.}4$ m$,$ and they are at a place where g $=9\mathrm{.}8$ m$/$s$2.$ With the coupling spring connected, one pendulum is clamped and the period of the other is found to be $1\mathrm{.}25$ sec exactly. i$.$ With neither pendulum clamped, what are the periods of the two normal modes? $[2$ marks$]$ ii$.$ What is the time interval between successive maximum possible amplitudes of one after one pendulum is drawn aside and released?