In this multiple-day activity, students measure the time it takes balls made of different materials to roll down inclines of varying lengths and heights, then make inferences about the relationship among the variables involved. Teachers are encouraged to act as facilitators while students decide which variables are important and can be measured, how best to collect the data, and how to interpret the results. Student input is elicited at all stages of the activity. Diagrams of the experimental apparatus, sample data tables, and suggestions for questions to guide students' thinking are included. Internet extensions are also provided. This lesson plan is adapted from an article that appeared in the November-December 1995 issue of Mathematics Teaching in the Middle School. (author/sw)

This hands-on lesson fits in Engineering and Science Technologies career-technical classrooms and in academic physics and mathematics classrooms. It is a great hands-on math application because students must apply formulas and measurement tools to find length, area, volume, and angle measures to appropriate levels of precision. The activity encourages students to think about the mathematics as they make conjectures about what happens to speed when height is changed. They explore how changing one variable affects the others. The weight of the balls and length of inclined planes are held constant. The lesson's goal is for students to make appropriate inferences regarding the relationships among the variables. This lesson can be modified by having students use spreadsheets to create charts to document the results and support their conclusions and by having groups make class presentations based on their findings. (jrs)