Many systems contain feedback mechanisms that serve to keep changes within specified limits. Cells continually divide to make more cells for growth and repair. Students will understand graph relationships between variables by studying topics such as exponential growth and decay, by conducting a series of numerical experiments using a computer model, and by conducting a variety of physical experiments. Collect and graph water bottle rocket data using data chart handout and graphboard tablet. Generate water bottle rocket data using Water Rocket Fun .
Complete water can experiment to investigate exponential growth.
Discuss limitations of initial models. Modify initial exponential growth models to include carrying capacity. Student ease making graphical connections between data sets. Even with similar results, scientists may wait until an investigation has been repeated many times before accepting the results as correct. If more than one variable changes at the same time in an experiment, the outcome of the experiment may not be clearly attributable to any one of the variables.