$60\mathrm{.}0$ g block attached to a horizontal spring is held at $8\mathrm{.}00$ cm from its equilibrium

position and released at t $=0.$ Its period is $0\mathrm{.}900$ s$.$ Find: $($a$)$ the displacement x at $1\mathrm{.}20$ s; $($b$)$ the

velocity when x $=-5\mathrm{.}00$ cm; $($c$)$ the acceleration when x $=-5\mathrm{.}00$ cm; $($d$)$ the total energy.