Explore key concepts in physics through this 13-minute lecture on internal energy from the Matter and Interactions series. Dive into a comprehensive review of previous chapters before delving into spring potential energy, thermal energy, power, and air resistance. Gain valuable insights into these fundamental physics principles, enhancing your understanding of how energy behaves within various systems. Perfect for students and enthusiasts looking to deepen their knowledge of physics, this lecture provides a concise yet thorough examination of essential topics in the field.