I$$d like to ask an expert

IMPORTANT NOTE: This cannot be solved using $.$

A mass of $0\mathrm{.}38$kg is attached to a spring and set into oscillation on a horizontal frictionless surface. The simple harmonic motion of the mass is described by x$($t$)=(0\mathrm{.}28$m$)$cos$[(20$rad$//$s$)$t$].$Determine the following.

$($a$)$amplitude of oscillation for the oscillating mass

I

m

$($b$)$force constant for the spring

$|$N$/$m

$($c$)$position of the mass after it has been oscillating for one half a period

m

$($d$)$position of the mass one$-$third of a period after it has been released

$|$m

$($e$)$time it takes the mass to get to the position x$=-0\mathrm{.}10$m after it has been released

s