Final answer:
If the net work on an object is negative, the object is slowing down, which indicates work is done against the object's motion leading to a decrease in kinetic energy.
Step-by-step explanation:
When the net work done on an object is negative, it generally means the object is slowing down. The work is done against the object's motion, resulting in a decrease in its kinetic energy. The theorem of work and energy states that an object will slow down if its final kinetic energy is less than its initial kinetic energy, implying negative net work. Conversely, if the object speeds up, then the work done on it is positive because the kinetic energy has increased. Net work is calculated by considering all the forces acting on the object, and it is given by the equation Wnet = Fnet d cos θ, where Fnet is the net force on the object, d is the displacement, and θ is the angle between the force and displacement vectors.