Final answer:
The principle that is equivalent to the conservation of energy is The first law of thermodynamics. It states that energy within an isolated system is constant and can be transformed but not created or destroyed. It is distinct from Newton's laws and the second law of thermodynamics.
Step-by-step explanation:
The principle equivalent to the conservation of energy is b. The first law of thermodynamics. This law states that the total energy of an isolated system is constant; energy can be transformed from one form to another, but cannot be created or destroyed. In other words, the change in internal energy of a system is equal to the net heat transfer into the system minus the net work done by the system. This law is expressed in the formula that the change in internal energy ΔU equals the heat added to the system Q minus the work done by the system W (ΔU = Q - W).
Newton’s first law, often known as the law of inertia, deals with the motion of a body and states that a body at rest will remain at rest, and a body in motion will remain in motion unless acted upon by a net external force. Consequently, this law does not directly relate to energy conservation. Newton’s second law relates force to the motion of a body and defines how the velocity of a body changes when it is subjected to an external force. The second law of thermodynamics, on the other hand, relates to the directions of natural processes and entropy, making a statement that heat energy cannot spontaneously transfer from a colder body to a hotter one. It does not directly describe the conservation of energy principle.