Answer
$\approx 1299038 J$
Work Step by Step
Horizontal component of the force is: $F=1500 cos 30 ^\circ$
$F=1500 cos 30 ^\circ=1500 \times \frac{\sqrt 3}{2}=750 \sqrt 3 N$
$d =1 km =1000 m$
As we know the work done is calculated as:
$ W= F.d$
Thus,
$ W=( 750 \sqrt 3 N) (1000 m)$
$W= 750000\sqrt 3 Nm $
$W \approx 1299038 J$