Answer
Please see the work below.
Work Step by Step
We know that the force of friction should be equal to the weight of the bat that is
$F_{friction}=F_{gravity}$
$\implies \mu n=mg$
$\mu (ma)=mg$
This simplifies to:
$a=\frac{g}{\mu}$
$a=\frac{9.8}{0.86}=11\frac{m}{s^2}$
