The best way of understanding the physics is to solve physics problems. This is the fourth book from the series Baby Steps In Physics. A student is wondering," How do I start? From where do I start? What formula should I use? " As with the previous books in the series, the book tries to answer these questions. The book features problems and solutions worked out in detail. The problems are arranged by increasing level of difficulty that allows the student to use this book independently. Indeed, this book is only a fourth step towards understanding how to solve physics problems. However, the book encourages personal confidence in problem-solving and develops the student's knowledge of physics.Baby Steps In Physics is recommended, but not limited to, high school and undergraduate students.