The law states that during energy transformations, the total energy of a system remains constant. Energy can change from one form to another, but the total amount of energy in the system remains unchanged.

Yes, the law of conservation of energy applies to all situations and all types of energy transformations, whether mechanical, chemical, thermal, or others.

The total energy of a system remains the same before and after energy transformations. Energy may change from kinetic to potential, thermal, or other forms, but the total energy remains constant.

During free fall, the total mechanical energy of the object remains constant, as the decrease in potential energy is equal to the increase in kinetic energy.

The total mechanical energy of an object is the sum of its kinetic energy and potential energy.