Activity 1—Graphing Your Motion Notes for Teachers

Concepts

Function explored: linear

Materials

Ÿcalculator (see page 2 for available models)

ŸCBR 2™ motion detector

Ÿunit-to-CBR 2™ or I/O unit-to-unit cable

ŸEasyData application or RANGER program

ŸMasking tape

ŸMeter stick

Hints

This experiment may be the first time your students use the CBR 2™ motion detector. A little coaching on its use now will save time later in the year as the CBR 2™ motion detector is used in many experiments. The following are hints for effective use of the

CBR 2™ motion detector:

0In using the CBR 2™ motion detector, it is

important to realize that the ultra sound is emitted in a cone about 30° wide. Anything within the cone of ultrasound can cause a reflection and possibly an accidental measurement. A common problem in using motion detectors is getting unintentional reflections from a desk or chair in the room.

0Often unintended reflections can be minimized by tilting the CBR 2™ motion detector slightly.

0If you begin with a velocity or acceleration graph and obtain a confusing display, switch back to a distance graph to see if it makes sense. If not, the CBR 2™ motion detector may not be properly targeting the target.

0The CBR 2™ motion detector does not properly detect objects closer than 15 cm. The maximum range is about 6 m, but stray objects in the wide detection cone can be problematic at this distance.

0Sometimes a target may not supply a strong reflection of the ultrasound. For example, if the target is a person wearing a bulky sweater, the resulting graph may be inconsistent.

0If the velocity and acceleration graphs are noisy, try to increase the strength of the ultrasonic reflection from the target by increasing the target’s area.

You may want to have your students hold a large book in front of them as they walk in front of the CBR 2™ motion detector. This will produce better graphs because it smoothes out the motion.

Typical plots

Distance vs. Time

Matching Distance vs. Time

Answers to questions

9.The slope of the portion of the graph corresponding to movement is greater for the faster trial.

Results will probably vary between groups as they may walk at different rates.

Walking towards the motion detector will produce a negative slope. While walking away from the motion detector will produce a positive slope.

12.Note that the slope is close to zero (if not zero) when standing still. The slope should be zero, but expect small variation due to the variation in collected data.

10 GETTING STARTED WITH THE CBR 2™ SONIC MOTION DETECTOR

© 2000 VERNIER SOFTWARE & TECHNOLOGY

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Texas Instruments CBR 2 manual Activity 1-Graphing Your Motion Notes for Teachers
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CBR 2 specifications

Texas Instruments has long been a prominent player in the field of educational technology, and the CBR 2 (Calculator-Based Ranger 2) is a testament to their commitment to enhancing the learning experience, particularly in the realms of mathematics and science. Designed to complement graphing calculators, the CBR 2 is a versatile data-collection device that empowers students and educators to explore real-world phenomena through hands-on experimentation.

One of the main features of the CBR 2 is its ability to capture a wide array of data through various sensors. The device is equipped with an array of built-in sensors that can measure motion, including speed and distance. This makes it an invaluable tool for physics experiments, allowing students to visualize concepts such as speed, acceleration, and trajectory.

The CBR 2 utilizes ultrasonic technology to detect distance through sound waves. This feature enables students to conduct experiments that demonstrate principles of sound and motion in a tangible way. With a range of up to 6 meters, the CBR 2 provides accurate and reliable measurements that can be graphically represented using compatible Texas Instruments graphing calculators.

The device is highly user-friendly, with simple interfaces that allow users to easily collect and analyze data. The integration with graphing calculators simplifies the process of data visualization, enabling students to create graphs in real time as they conduct experiments. This capability is particularly beneficial in encouraging interactive learning and fostering a deeper understanding of scientific principles.

The CBR 2 is designed to be portable and durable, making it suitable for classroom settings as well as outdoor experiments. Its compact size and lightweight construction ensure that it can be easily transported, allowing educators to take learning beyond the confines of the classroom.

The CBR 2 also supports various modes of data collection, including Event Mode, which allows users to trigger data collection based on specific events. This feature is useful in demonstrating concepts such as projectile motion and collisions, providing students with hands-on experience that enhances their learning.

In summary, Texas Instruments' CBR 2 is a powerful educational tool that enables students to collect, analyze, and visualize data in an engaging manner. With its built-in sensors, ultrasonic technology, and seamless integration with graphing calculators, the CBR 2 stands out as a versatile device that enriches the educational experience. It not only provides a platform for conducting experiments but also cultivates critical thinking skills and a deeper understanding of scientific concepts, preparing students for a future in STEM fields.
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