$($I$)$ A $1\mathrm{.}28-$kg mass oscillates according to the equation x $=0\mathrm{.}650$ cos $7\mathrm{.}40$ t where x is in meters and t in seconds. Determine $($a$)$ the amplitude, $($b$)$ the frequency, $($c$)$ the total energy, and $($d$)$ the kinetic energy and potential energy when x $=0\mathrm{.}260$ m$.$