Linear Models and Latex Explosion!
Students work as engineers to test the strength of latex tubing through testing, data collection and data analysis.Copyright Center for Compact and Efficient Fluid Power (CCEFP). Used with permission.
Students use latex tubes and bicycle pumps to conduct experiments to gather data about the relationship between latex strength and air pressure. Then they use this data to extrapolate latex strength to the size of latex tubing that would be needed in modern passenger sedans to serve as hybrid vehicle accelerators, thus answering the engineering design challenge question posed in the first lesson of this unit. Students input data into Excel spreadsheets and generate best fit lines by the selection of two data points from their experimental research data. They discuss the y-intercept and slope as it pertains to the mathematical model they generated. Students use the slope of the line to interpret the data collected. Then they extrapolate with this information to predict the latex dimensions that would be required for a full-size hydraulic accumulator installed in a passenger vehicle.
To create functional and effective designs, engineers collect and analyze data on various design elements. Often, engineers use prototypes or smaller-sized models of the design components in their experimentations and research. To understand how full-scale designs will function, they use statistical models to extrapolate information. In this activity, students implement a design strategy that allows them to model the relationship between latex strength and air pressure. This model allows them to generalize to large-scale latex tubing, similar to the work of real engineers.
After this activity, students should be able to:
- Carry out a simple design experiment by measuring the quantities of two variables.
- Generate a line of best fit using two data points for a linear relationship and determine the equation of the line.
- Use appropriate language to interpolate given data points in a linear relationship.
- Extrapolate and make predictions, given a collection of data points.
- In paragraph format, describe the steps of the engineering design process from start to finish.