Whenever an object is falling, its potential energy is decreasing and its kinetic energy is increasing.
Olivia's potential energy is decreasing and her kinetic energy is increasing as she moves toward the right side of the picture, all the way from W, through X, to the bottom of the arc.
Potential energy is due to position of the body. In this case it is determined by the height.
P.E. = m g h
At the highest point potential energy is maximum. As the Olivia swings down, potential energy converts to kinetic energy. Thus, at point W, potential energy is decreasing and kinetic energy is increasing. Kinetic energy would be maximum at lowest point.
