$8\mathrm{.}5-$kg block is released from point A with speed of initial speed $2\mathrm{.}5$m$/$s$.($Block is given a push$)($Point A is $3\mathrm{.}4$m high$).$ The track is frictionless except for the portion between points B and C $(6\mathrm{.}8$m$).$ The block travels down the track, hits a spring of force constant $1,650$N$/$m$,$ and compresses the spring $0\mathrm{.}28$m from its equilibrium position before coming to rest momentarily.

Determine the coefficient of kinetic friction between the block and the rough surface between B and C$.$

Input your answer to three decimal places.