A particle is moved from point X to point Y under a force field. The work done depends only on the initial and final speeds. Which one of the following is correct?

The statement is a direct application of the Work-Energy Theorem. According to this theorem, the net work done by all forces acting on a particle is equal to the change in its kinetic energy (ΔK). The formula for kinetic energy is K = ½mv2. Therefore, the net work done is:

Wnet = ΔK = ½mvf2 - ½mvi2

Since the mass (m) of the particle is constant, the work done depends solely on the initial speed (vi) and the final speed (vf). Option A is incorrect because the work done by a conservative force depends on the initial and final positions (potential energy change), not speeds. Option C is incorrect because the theorem applies to both constant and variable forces. Option D is incorrect because work can be negative, leading to a decrease in speed.