Energy Conservation: The First Law of Thermodynamics

This lecture discusses the first law of thermodynamics, focusing on energy conservation. The instructor begins by reviewing the fundamental laws of physics, emphasizing mass conservation and Newton's second law before introducing the Reynolds transport theorem for energy conservation. The lecture defines total specific energy and its components: internal energy, kinetic energy, and potential energy. The instructor explains how energy changes within a system, detailing the contributions of heat transfer and work done on the system. The first law of thermodynamics is presented as a Lagrangian law for fluid systems, highlighting the rate of change of total energy. The discussion includes the concept of mechanical power, differentiating between shaft power and power due to normal stresses. The lecture concludes by relating the energy equation to the Bernoulli equation, illustrating how energy conservation principles apply to fluid dynamics and emphasizing the importance of understanding losses due to viscosity. The instructor encourages students to practice applying these concepts in exercises.