The work done by the force acting on an object is zero if the displacement of the object (a) is in the opposite direction of the direction of force (b) is in the same direction of the direction of force (c) is in perpendicular direction of the direction of force (d) none of above

In physics, work done (W) is defined as the dot product of the force vector (F) and the displacement vector (d), expressed mathematically as W = Fd cos θ. The angle θ represents the orientation between the force and the displacement. When the displacement is in the same direction as the force (θ = 0°), the work is positive. When the displacement is in the opposite direction (θ = 180°), the work is negative, as seen with friction. However, if the force and displacement are perpendicular to each other (θ = 90°), the cosine of the angle becomes zero (cos 90° = 0). Consequently, the product results in zero work being done. Examples include centripetal force in circular motion, where the force is always perpendicular to the instantaneous displacement.