The figure shows a block $($mass unknown$)$ that slides along a track that is frictionless until it slides through a region of friction $(d=6\mathrm{.}00$ m $)$ on the last plateau, where the coefficient of friction is ${}_k=0\mathrm{.}400.$ At the left, the block has height $5\mathrm{.}00$ m and speed $8\mathrm{.}00\frac{m}{s}.$ What is its speed $(\frac{m}{s})$ at the far right, after it emerges from the friction region?

$5\mathrm{.}88$

$10\mathrm{.}3$

$14\mathrm{.}3$

$1\mathrm{.}43$

$9\mathrm{.}56$

$7\mathrm{.}23$

$11\mathrm{.}4$

$2\mathrm{.}56$

$8\mathrm{.}70$

$12\mathrm{.}4$