Extended Classical Mechanics (ECM) explores the dynamic relationship between matter mass and apparent mass, which is crucial for understanding mass-energy interactions. In ECM, inertial mass transforms into negative apparent mass as it gains kinetic energy, leading to an energy displacement effect. As acceleration increases, this effect becomes more pronounced, altering the system's effective mass. In gravitational systems, the exchange between potential energy (PE) and kinetic energy (KE) naturally regulates apparent mass, shaping force-energy interactions.