Answer:
Only when the force is applied in the same direction as the displacement of the object on which it acts, it does maximum work. This is because the work done by a force is given by the dot product of the force and displacement vectors. The dot product of two vectors is maximum when they are parallel to each other. Therefore, when a force is applied in the direction of displacement, it does maximum work.
When a force is applied perpendicular to the displacement, it does no work at all. This is because the dot product of two perpendicular vectors is zero. When a force is applied at an angle to the displacement, it does some work but not maximum.
It's important to note that the amount of work done by a force also depends on its magnitude and the distance over which it acts. The greater the magnitude of the force and the longer the distance over which it acts, the more work it will do.
In summary, a force does maximum work only when it is applied in the same direction as the displacement of the object on which it acts.