K in the equation K=1/2mv^2 represents the kinetic energy of an object with mass m and velocity v, not the change in kinetic energy. To determine the change in kinetic energy, one must calculate the difference between final and initial kinetic energy, expressed as Kfinal - Kinitial, which equals the total work done (Wtotal). The discussion also touches on potential energy, emphasizing that only changes in energy can be calculated, and absolute kinetic energy requires an arbitrary reference point for a body at rest. The conversation highlights the importance of defining a reference value for kinetic energy when considering a stationary object. Understanding these concepts is crucial for accurately analyzing energy transformations in physics.