Work, Energy, and Simple Machines

What “Work, Energy, and Simple Machines” begins with

Work, Energy, and Simple Machines Chapter 7 In earlier Chapters 4 and 6, you have learnt how forces change the motion of objects, and how kinematic equations and Newton’s laws can be used to analyse motion. But when forces change with time or act in complicated ways, applying these laws directly can become difficult. Is there a simpler and more powerful way to understand such situations?