Answer
Please see the work below.
Work Step by Step
We know that:
$W_a=F_a.d$
We plug in the known values to obtain:
$W_a=20.(0.50)cso30^{\circ}$
$Wa=8.66J$
and $W_G=F_G.d$
We plug in the known values to obtain:
$W_G=(3.00)(9.80)(0.50)cos120^{\circ}=-7.35J$
Thus: $W_a+W_G=1.31J$.
