Explanation:
When the force and displacement are in the same direction,the work done is always positive.
work done is defined as dot product of force and displacement.
[tex]workdone=force.displacement[/tex]
When the absolute value of the angle between force and displacement is within [tex]90^{0}[/tex],dot product is positive.
When the angle between force and displacement is [tex]0^{0}[/tex]
force and displacement are in the same direction.
In the given question,force and displacement are in same direction,so the work done is positive.