Answer:
0 (Zero)
Step-by-step explanation:
Definition of work done states that ,
Work done on an object is the force applied on that object in the direction of Displacement of the object .
means that ,
W = F.dS (Dot product of Force and displacement)
When the wall is acted upon by the force of 20 N , Wall does not move ,
Thus , displacement of the wall is zero.
So, W = 20×0 = 0.
Thus, Work done on the wall is zero.