If the work done by a body on applying a constant force is directly proportional to the distance travelled by the body, then express this in the form of an equation in two variables by taking the constant force as 4 units. From the graph, find the work done when the distance travelled is (i) 2 units (ii) 0 units (iii) 5 units.

Work done = W


Force = F = 4


Distance = d


Since, Work done Distance


Therefore, W d


W = F× d


W = 4d


Let d = 0


W = 4 × 0 = 0


Let d = 2


W = 4 × 2 = 8


Let d = 5


W = 4 × 5 = 20


Plotting them we get the following graph,



The blue line indicates the required graph of W = 4d


Clearly from the graph,


(i) When d = 2 units


then, W = 8 units


(ii) When d = 0 unit


then, W = 0 unit


(iii) When d = 5 units


then, W = 20 units


43