In this article, I will cover one of the essential topics of fluid mechanics as the title shows three crucial topics—the first concerns the conservation of mass and how it plays a critical role in our daily life. The next one involves the conservation of kinetic and potential energy and is all about the flow energy of a fluid stream. The Bernoulli equation is all about considering the energies, handling them of fluid, and neglecting the viscous forces. The last topic is energy equations, which is about the conservation of energy principle. As we know that while dealing with energy in fluid mec ...