A horizontal block$-$spring system with the block on a frictionless surface has total mechanical energy E $=37\mathrm{.}6$ J and a maximum displacement from equilibrium of $0\mathrm{.}254$ m$.$

$($a$)$ What is the spring constant?

N$/$m

$($b$)$ What is the kinetic energy of the system at the equilibrium point?

J

$($c$)$ If the maximum speed of the block is $3\mathrm{.}45$ m$/$s$,$ what is its mass?

kg