Final answer:
A pendulum's kinetic energy decreases and its potential energy increases at the highest swing points, with the pendulum having the highest kinetic energy at the lowest swing point. Due to friction and air resistance, energy is lost and the pendulum's motion gradually diminishes until it comes to a stop.
Step-by-step explanation:
As a pendulum comes to a stop, its kinetic energy decreases while its potential energy increases at the highest points of its swing. When the pendulum is at the lowest point of its swing, it has the highest kinetic energy because all the potential energy has been converted into kinetic energy. This transformation between kinetic and potential energy continues back and forth due to the conservation of energy in the pendulum system until external forces, such as air resistance and friction at the pivot point, dissipate the energy and bring the pendulum to a stop.
In the absence of other external forces, the conversion of energy from potential to kinetic would be seamless, and the pendulum would continue swinging indefinitely. With friction and air resistance, energy is gradually lost to the environment, and the amplitude of the pendulum's swing decreases until it eventually comes to rest. Thus, at each swing, the potential energy is not completely converted into kinetic energy; some of it is lost, leading to a gradual decline in the pendulum's motion.