Many real-life processes can be characterised by rapid changes in their state. Some of these changes begin impulsively and are not negligible. For changes such as these, mathematical models called non-instantaneous differential equations are created. These models give rise to a new, hybrid dynamical system that can be used for many different purposes. Using a variety of equations, examples and solutions, this book will be an essential guide for researchers, graduate students and those interested in applied mathematics and related fields.