A $6-$kg block is attached to a spring, and oscillates horizontally on a frictionless tabletop. The spring has constant k$=1\mathrm{.}06$e$3$N$/$m$.$ The block as speed v$=4\mathrm{.}4$m$/$s when the spring is stretched a distance $$s $=10$cm from equilibrium.

$($a$)$

What is the total mechanical energy of the block$-$spring system?