Work and energy are important concepts in physics as well as in our day to day life. Everyday we spend a lot of time and effort doing things such as walking, writing, climbing stairs, reading books. In its everyday sense, the term work means to do something that takes physical or mental effort. But in physics, work has a distinctly different meaning. In this unit we study the concepts of work and the related concepts of kinetic energy, potential energy, and power. In addition, we will use the principle of conservation of mechanical energy to solve a variety of problems.