To calculate the kinetic energy (KE) of the slowest emitted photoelectron, one must consider the photoelectric effect, where the energy of the incoming photon (hf) equals the work function of the metal. When the photon energy matches the work function, the emitted electron has zero kinetic energy, resulting in a velocity of zero. Thus, the slowest emitted photoelectron is characterized by having no kinetic energy, as it does not possess enough energy to overcome the work function. This means that the lowest possible KE is indeed zero, which corresponds to a stationary electron. Understanding this concept is crucial for accurately interpreting photoelectron emission in experiments.