Answer
There is not enough information.
Work Step by Step
We can apply conservation of energy:
$K_i+U_i+W = K_f+U_f+\Delta E_{th}$
Since the system's potential energy decreases, $U_i \gt U_f$
Since the system does work on the environment, $W \lt 0$
Therefore, it is not clear whether $K_i = K_f$, $K_i \gt K_f$ or $K_i \lt K_f$
There is not enough information.