If the work done by a body on application of a constant force is directly proportional to the distance travelled by the body,express this in the form of an equation in two variables and draw the graph of the same by taking the constant force as $5$ units. Also,read from the graph the work done when the distance travelled by the body is:
$(i)$ $2$ units
$(ii)$ $0$ units

(N/A) Constant force is $5$ units. Let the distance travelled $= x$ units and work done $= y$ units.
Since,$\text{Work done} = \text{Force} \times \text{Displacement}$
$\Rightarrow y = 5 \times x$
$\Rightarrow y = 5x$
Drawing the graph:
We have $y = 5x$.
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.
From the graph:
$(i)$ When distance travelled $= 2$ units,then $x = 2$,which gives $y = 10$.
Therefore,$\text{Work done} = 10$ units.
$(ii)$ When distance travelled $= 0$ units,then $x = 0$,which gives $y = 5(0) = 0$.
Therefore,$\text{Work done} = 0$ units.