$($II$)$ A $1\mathrm{.}60-$kg object oscillates at the end of a vertically hanging light spring once every $0\mathrm{.}68$ s$.($a$)$ Write down the equation giving its position as a function of time t$.$ Assume the spring was initially compressed $16$ cm from the equilibrium position $($where $),$ and then was released. $($b$)$ How long will it take the object to get to the equilibrium position for the first time? $($c$)$ What will be its maximum speed? $($d$)$ What will be its maximum acceleration, and where will it first be attained?