Discuss the differences between using a model to predict versus using one to explain a real-world system. Think of some situations in which you would like to explain a system. Likewise, imagine other situations in which you would want to predict a system.

For the scenarios presented in Problems 9-17, identify a problem worth studying and list the variables that affect the behavior you have identified. Which variables would be neglected completely? Which might be considered as constants initially? Can you identify any submodels you would want to study in detail? Identify any data you would want collected.