# Math 224-01: Differential Equations: Reading Homework 1.5

1. Introduction to Modeling and Systems : what is modeling? how are models used to explain outcomes of observable situations?
1. Models and Systems : what is a differential system?
1. Point : what is the order of a differential system?
2. Point : what is normal form for a first-order system?
3. Point : what is a linear differential system? what are the different parts of the system?
2. Radioactive Decay : what is the decay law?
1. Point : what differential equation do we get from the decay law? what is a rate-constant?
2. Point : what is the half-life of an element? what does it often let us calculate?
3. Motion : what does Galileo tell us about motion?
1. Point : what is Newton's second law?
2. Point : how similar is the model for the wiffle ball to that for a parachuter?
4. Dynamical Systems : what are natural variables? natural laws? natural parameters?
1. Point : what is a state variable?
2. Point : what is a dynamical system?

Math 224-01: Differential Equations: Reading Homework 1.5