The object will have the biggest total work done on it by all forces during its motion if the net force acting on the object is in the same direction as the displacement of the object.
Work is defined as the product of force and displacement, W = F * d * cosθ, where W is the work done, F is the force applied, d is the displacement of the object, and θ is the angle between the force vector and the displacement vector.
When the force and displacement vectors are in the same direction (θ = 0°), the cosine of 0° is 1, resulting in maximum work done. In this case, the force applied is fully contributing to the displacement, resulting in the greatest amount of work.
Conversely, when the force and displacement vectors are perpendicular (θ = 90°), the cosine of 90° is 0, resulting in no work done. The force is not contributing to the displacement, leading to zero work.
Therefore, the object will experience the biggest total work done on it when the net force acting on it is in the same direction as its displacement.