Texas Instruments CBR 2 Teacher Information, Explore data graphically, Explore data numerically

Teacher Information

How might your classes change with a CBR 2™ sonic motion detector?

The CBR 2™ motion detector is an easy-to-use system with features that help you integrate it into your lesson plans quickly and easily.

The CBR 2™ motion detector offers significant improvements over other data-collection methods you may have used in the past. This, in turn, may lead to a restructuring of how you use class time, as your students become more enthusiastic about using real-world data.

0You’ll find that your students feel a greater sense of ownership of the data because they actually participate in the data-collection process rather than using data from textbooks, periodicals, or statistical abstracts. This impresses upon them that the concepts you explore in class are connected to the real world and aren’t just abstract ideas. But it also means that each student will want to take his or her turn at collecting the data.

0Data collection with CBR 2™ motion detector is considerably more effective than creating scenarios and manually taking measurements with a ruler and stopwatch. Since more sampling points give greater resolution and since a sonic motion detector is highly accurate, the shape of curves is more readily apparent. You will need less time for data collection and have more time for analysis and exploration.

0With CBR 2™ motion detector students can explore the repeatability of observations and variations in what-if scenarios. Such questions as “Is it the same parabola if we drop the ball from a greater height?” and “Is the parabola the same for the first bounce as the last bounce?” become natural and valuable extensions.

0The power of visualization lets students quickly associate the plotted list data with the physical properties and mathematical functions the data describes.

Other changes occur once the data from real-world events is collected. CBR 2™ motion detector lets your students explore underlying relationships both numerically and graphically.

Explore data graphically

Use automatically generated plots of distance, velocity, and acceleration with respect to time for explorations such as:

0What is the physical significance of the y-intercept? the x-intercept? the slope? the maximum? the minimum? the derivatives? the integrals?

0How do we recognize the function (linear, parabolic, etc.) represented by the plot?

0How would we model the data with a representative function? What is the significance of the various coefficients in the function (e.g., AX2 + BX + C)?

Explore data numerically

Your students can employ statistical methods (mean, median, mode, standard deviation, etc.) appropriate for their level to explore the numeric data. When you exit the EasyData application or RANGER program, a prompt reminds you of the lists in which time (L1), distance (L2), velocity L3), and acceleration (L4) are stored.

32 GETTING STARTED WITH THE CBR 2™ SONIC MOTION DETECTOR © 1997, 2004, 2006 TEXAS INSTRUMENTS INCORPORATED