A reaction inside a cylindrical container with a movable piston causes the volume to change from $13\mathrm{.}0$ L

to $21\mathrm{.}0$ L

while the pressure outside the container remains constant at $0\mathrm{.}975$ atm. $($The volume of a cylinder is V$=\backslash$pi $$r$2$h

$,$ where h

is the height; $1$ L$\backslash$times atm$=101\mathrm{.}325$J

$.)$ The diameter of the piston is $17\mathrm{.}0$ cm

$.$ How far does the piston move?