The first law of thermodynamics states that. How is this also a statement of the principle of conservation of energy?

A. A change in internal energy causes work to be done and heat to flow into the system.

B. The heat that flows into the system is transformed into work and a change in internal energy.

C. The energy that flows into the system is transformed into heat and work.

D. The work that is done by the piston is transformed into heat and a change in internal energy.

The answer is a change in internal energy causes work to be done and heat to flow into the system.

Explanation:

The first law of thermodynamics is a similar version of the law of conservation of energy where the energy can neither be created nor be destroyed, it can be transformed from one form to the other. It also defines that the work is done and heat flowing into the system is due to the change in internal energy. The sum of all energy including kinetic and potential energy except the displaced energy to the surrounding is known as internal energy. ΔU represents the change in internal energy of the system, Q represents the net heat transferred into the system, and W represents the net work done by the system. So + ve Q adds energy to the system and = ve W takes energy from the system. Thus ΔU=Q-W.

i believe that the answer is a