A $12\mathrm{.}8-$kg object hangs in equilibrium from a string with a total length of

$6\mathrm{.}00$ m

and a linear mass density of

$=0\mathrm{.}00300$ kg$/$m$.$

The string is wrapped around two light frictionless pulleys that are separated by a distance of

d $=2\mathrm{.}00$ m$.$