1, the formula of conservation law of mechanical energy: E _ k 1+E _ p 1 = E _ K2+E_p2, where e _ k1and e _ k2 are the kinetic energy of the object in the initial state and the final state, respectively, and e _ p1. This formula shows that the kinetic energy and potential energy (including gravitational potential energy and elastic potential energy) of an object can be transformed into each other, but the total energy of mechanical energy remains unchanged.

2. The formula of the law of conservation of energy: Δ e = E _ terminal-E _ initial, where Δ e is the change of system energy, e _ terminal is the total energy of the final state of the system, and e _ initial is the total energy of the initial state of the system. This formula shows that energy will neither be generated out of thin air nor disappear out of thin air, but will only be transformed from one form to another, or from one object to another, and the total amount will remain unchanged during the transformation or transfer.