Starting with algebraic descriptions of individual components (such as resistors), the class develops tools for modeling engineered systems. Differential equations are key ingredients, so we will spend significant time learning how to derive differential equations from component descriptions. One of the key ideas in this class is that electrical, mechanical, and chemical systems may seem very different from each other but often have very similar behavior, allowing us to draw powerful analogies between them. Case studies from several areas of engineering will be used to illustrate the modeling techniques, including examples from robotics, power networks, exoskeletons, biomechanics, system identification, and active sensing. Students will be encouraged to do hands-on experiments that demonstrate the techniques.