Reynolds transport theorem

Reynolds Transport Theorem is a principle used in physics and engineering to relate the changes in a quantity (like mass or energy) within a moving system to what's happening at its boundaries. Essentially, it helps us understand how the flow of a fluid or movement of particles affects the overall properties of a system. If you think of a river, the theorem helps explain how the water and any substances it carries change as it flows, considering both what’s within the river and what exits or enters at the banks.