A child is swinging back-and-forth on the swing changes in her kinetic and potential energy are happening each moment at which point or multiple points in her swinging with each of these two types of energy be at a maximum
The kinetic energy of the child on the swing will be at a maximum when she is at the lowest point of the swing, just as she is starting to swing back up. This is because the child is moving at her fastest speed at this point.
The potential energy of the child on the swing will be at a maximum when she is at the highest point of the swing. This is because potential energy is related to the height of an object above the ground, and at the highest point of the swing, the child is at her maximum height above the ground.
So, at the lowest point of the swing, the kinetic energy will be at a maximum, and at the highest point of the swing, the potential energy will be at a maximum.