Constant force is $5$ units. Let the distance travelled $= x$ units and work done $= y$ units

since,   Work done $=$ Force $\times$ Displacement 

 $\Rightarrow $                $y=5 \times x$

$\Rightarrow $                $ y=5 x$

Drawing the graph

We have $ y=5 x$

When $x =0,$ then $y =5(0)=0$

When $x =1,$ then $y =5(1)=5$

When $x =1.5,$ then $y =5(1.5)=7.5$

$\therefore $    We get the following table :

$x$	$0$	$1$	$1.5$
$y$	$0$	$5$	$7.5$

Plotting the ordered pairs $(0,\,0)$, $(1,\,5)$ and $(1.5,\,7.5)$ on the graph paper and joining the points, we get a straight line $OB$. 

From the graph, we get

$(i)$ Distance travelled $= 2$ unit

$\therefore $  $x=2$, then  $y=10$ units

$\Rightarrow $ Work done $=10$ units.

$(ii)$ Distance travelled $=0$ units

$\therefore $       $y=5 x \Rightarrow y=5(0)=0$

$\therefore $       Work done $=0$ unit.