Energy cannot be created or destroyed it can only be transformed into a different kind of energy work or power.
If this is the case, then the energy likely left the system through external forces or heat dissipated into the environment.
When potential and kinetic energy are not equal, the 'leftover' energy likely transformed into other forms, such as heat or sound, or was dissipated due to friction or air resistance. All energy is conserved, so it doesn't disappear; it merely changes from one type to another. Understanding energy transformations helps clarify where this energy goes in different systems.
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