Innovative Uses
Testing Heat Packs
A popular, inexpensive, product sold in northern climes is a single-use packet that warms up upon "activation" and stays warm for a few hours. They come in different sizes, most are small enough to fit in an adult palm, and they're advertised as "hand warmers," "feet warmers," or generically as heat packs. The label of these heat packs tells the user to simply open the outer package before use, and the packet will warm gradually to about 38°C. It will remain warm for up to six hours.
The exothermic reaction that most of these hand warmers use is the simple rusting of iron. The package's label hints at this in the list of ingredients: iron, water, activated carbon, and salt. Some heat packs also list vermiculite as an ingredient. Those of us who have owned certain models of cars or trucks appreciate the psychological heat generated by our vehicles rusting away before our eyes, and now this vile chemical reaction has been packaged to do good.
There are two common heat pack products—reusable and single use. In this experiment, we tested the single-use heat packs.
We placed a heat pack in one of our new BioChamber 2000 units and measured the temperature ~1 cm above the heat pack. Because another word for rusting is oxidation, and oxidation sometimes involves oxygen, we used an Oxygen Gas Sensor to measure the change in O2 concentration in the sealed BioChamber.
The Logger Pro graph here shows some typical data for our experiment. We see this simple setup as a jumping-off point for several investigations, including
- Maximum temperature reached by a single-use heat pack
- Total time a heat pack stays warm
- Comparing a commercial heat pack vs. "homemade" heat pack
- Comparing a single-use heat pack vs. a reusable heat pack
- Determining the amount of iron in a heat pack
- Kinetic study of the redox reaction in a heat pack
This is a fun and easy experiment. Try it today and encourage your students to conduct their own research to discover how heat packs work.
Speed of Sound in a Snap
One of the experiments in our physics lab manuals has students determine the speed of sound in air by creating a short sound in a column of air, such as a hollow tube. A Vernier Microphone is used to pick up the initial sound and the echo of the sound from the end of the tube.
A graph of the data allows the student to determine the round-trip time for the sound. Knowing the time and the round-trip distance, they calculate the speed of sound. One challenge in the experiment is to create a short enough sound that it dies out before the echo is received. We used to recommend snapping your fingers to create the sound, but some students struggle with that.
We've come up with a better solution: Use a dog training clicker, readily available at pet supply stores. It creates a nice sharp sound that dies out quickly. Here are some sample data collected with a clicker and a fluorescent tube guard cut off to 1.17 m. From this data, the speed of sound was determined to be 344 m/s at room temperature.
What To Do With Old CBLs?
Nüsret Hisim (Walkersville HS, Walkersville, MD) was in the same situation as many other customers: He long ago updated his interfaces to newer LabPros or CBL 2s. Here are some creative ways he makes use of those older, original CBLs:
- Use them as stand-alone meters. The original CBL not only had a meter screen on the unit, but it also came with three inexpensive sensors—temperature, light, and voltage. Simply turn on the CBL, connect one of these sensors to Channel 1 of the CBL, and press the Mode button. You will have a great digital meter. No calculator program is necessary. Nüsret keeps one at each lab station to use as a digital thermometer.
- Use CBL sensors with newer interfaces. The CBL's temperature, light, and voltage probes all have BTA connectors and are auto ID. Simply connect them to a LabQuest, LabPro, or CBL 2, and start up your Vernier data-collection program. Make sure you gather up these very useful sensors before storing those CBLs on the back shelf!
- Put the CBLs back into service. We have customers who are new to a school who have found CBLs on a back shelf. They are unsure how to use them and give us a call.We are happy to help them set up their TI calculators with a data-collection program for their CBLs.
What Can I Do with a Vernier Charge Sensor?
The Vernier Charge Sensor is essentially an electroscope, but since it connects to a computer, you can do many more experiments than with the traditional device. There's an excellent and detailed article titled "Electrostatics with Computer-Interfaced Charge Sensors" by Robert Morse in The Physics Teacher, vol 44, November 2006, pages 498-502.
What types of activities can I perform with the Charge Sensor?
Vernier Charge Sensor | Order Code CRG-BTA | $75
Get Ready for the Ring
Nick La Rosa, a Level 2 boxing coach from Victoria, Australia, found he could use Vernier data-collection technology to improve the performance of his boxers. Nick has developed various tests to help him evaluate fitness levels of the boxers, as well as effectiveness of the training program.
Nick uses the Force Plate to evaluate jump and arm strength power rates. One boxer more than doubled his vertical jumping power, which Nick has attributed to the boxer's ranking as national champion. Nick also uses Logger Pro video analysis to compare a boxer's jab during strike and recoil.
Using this technique, Nick has been able to identify and correct inefficient technique that could leave a boxer open to counter punches or lessen the effectiveness of a counter attack. The graph above shows differences in grip strength using each hand, measured using a Vernier Hand Dynamometer. Studies have shown a direct correlation between grip strength and success in elite boxers.
Innovative Uses from the Journals
Three physics instructors from the University of British Columbhiia (Marina Milner-Bolotin, Andrzej Kotlicki, and Georg Rieger) conducted a survey to answer the question, "Can Students Learn from Lecture Demonstrations?" The lecture demonstrations used by these instructors are similar to the Interactive Lecture Demonstrations developed by David Sokoloff, Ron Thornton, and Priscilla Laws. They compared traditional demonstrations with "Interactive Lecture Experiments (ILE)". They found that the students learned more when the ILE process was followed as compared to traditional demonstrations. (Journal of College Science Teaching, Jan/Feb 2007).
The February 2007 issue of Mathematics Teacher included the article "Imagine Yourself in this Calculus Classroom," by Luajean Bryan, Walker Valley High School, Cleveland, TN. The article describes how her students gathered data during a hot-air balloon ride to explore concepts in calculus. They used a TI calculator and CBL to collect temperature data. They modeled the temperature data in Logger Pro. They also used the video analysis features of Logger Pro to analyze the motion of the shadow of a balloon.
Great Ideas from The Physics Teacher
Recent issues of The Physics Teacher have had many good ideas for teaching physics with our products:
"Experimenting with Guitar Strings," by Michael C. LoPresto, Henry Ford Community College (November 2006). This is a great article showing how to use Logger Pro and LabPro to do a study of the length of guitar strings and the frequencies they produce.
"The Energetics of Bouncing (Revisited)," by Eric Gettrust, West High School, Madison, WI (October 2006), explains how to use Logger Pro to graph and study the changes in energy as a dynamics cart bounces off a force sensor.
"Remote Experimentation Made Easy with LabVIEW™," by Perry A. Tompkins, Samford University (October 2006), explains how to publish data on a web site easily by using the National Instruments programming language LabVIEW. We have supported LabVIEW with all of our interfaces for years, so if you want a quick way to put data on a web site as it is collected, check out this article, or contact us.
"Recoil Experiments Using a Compressed Air Cannon," by Brett Taylor, Radford University, VA, (December 2006), shows how to use our Force Plate and Logger Pro to measure the impulse when launching various items like potatoes, wooden balls, and ping-pong balls from air cannons.
"A Demonstration of the Work-Kinetic Energy Theorem," by Martin Kamela, Elon University, NC (December 2006), shows how our Logger Pro, Motion Detector, and Dual-Range Force Sensor can be used to demonstrate this sometimes confusing concept.
"An Oscillating System with Sliding Friction," by Martin Kamela, Elon University, NC (February 2007), shows how to use Logger Pro, a Motion Detector, and a dynamics cart to study harmonic oscillation with damping. This system can be thought of as the mechanical equivalent of an LRC circuit.
"Playground Physics: Determining the Moment of Inertia of a Merry-Go-Round," by Stephen Van Hook, Adam Lark, Jeff Hodges, Eric Celebrezze, and Lindsey Channels, Bowling Green State University, OH (February 2007), shows how to use a portable data-collection system to make a real-world measurement of the moment of inertia. They calculated the result using both acceleration data and video analysis. They used a LabPro and a TI graphing calculator for the acceleration measurements, but you could soon use a LabQuest for this lab activity.
More Innovative Uses
Read more innovative uses such as accelerations in snowboarding, chemistry of bathtub tings, and more at www.vernier.com/innovate