7.3 | The Principle of Conservation of Energy
The principle of conservation of energy states that energy cannot be created or destroyed but can only change its form.
Swing systems such as swing of simple pendulum and swing of spring are always undergone transformation of energy between the gravitational or elastic potential energy with the kinetic energy in accordance with the principle of conservation of energy.
In a closed system, the energy change between potential energy and kinetic energy obeys the principle of the conservation of energy. Therefore, the total potential energy and kinetic energy in a closed swing system is constant.