In a recent review in its publication, School Science Review, the Association for Science Education (ASE) praises our Dynamics Cart and Track System with Motion Encoder for its ability to produce noise-free, position-time data. The article also highlights the option to analyze the data with our Logger Pro data-collection software or LabQuest App, both of which are “excellent and very easy to use.”
The Dynamics Cart and Track System with Motion Encoder (formerly known as the Motion Encoder System), recommended for high school and college classrooms, is a complete, revolutionary dynamics system with carts, track, and associated hardware, including a new optical motion encoder to record cart position. Recent updates to the system include an entirely redesigned cart that makes it easier than ever to attach a sensor or increase mass. The plunger cart also features a super-elastic trigger button that allows for a host of new collision types.
School Science Review—a quarterly periodical distributed to ASE members, university libraries, and education centers worldwide—featured the review in its March 2016 edition.
Dynamics experiments are a core part of many physics courses, and low-friction carts and tracks have long been a popular tool for use with Vernier sensors. Based on customer feedback, we have redesigned our carts and accessories, making a good system even better. Renamed the Dynamics Cart and Track System, the set is available with or without our unique Motion Encoder System, and with either a 1.2 or 2.2 meter track. Additional accessories, such as a pulley and pulley bracket, are also now included—all for an even lower price.
The carts have been redesigned from the axles up. It is much easier to attach sensors and masses to the carts, and, to facilitate classroom discussions, the carts now come in two colors. A new, triggered‑release mode for the spring plunger allows students to set up a superelastic collision between two carts—a collision where the kinetic energy increases. Such a collision still conserves momentum because the plunger spring force is internal to the two-cart system.
In Logger Pro, we configured the Motion Encoder so that the carts shared the same coordinate system, with the same zero position and positive direction. We started the experiment with the plunger cart at rest, and rolled the plain cart into the plunger cart. On impact, the carts explosively moved apart, with the plain cart reversing direction. The position graph shows the motion clearly, with the cart represented by the blue line rolling into, and then away from, the other cart. Note the complete absence of spikes or other noise in the graph traces, made possible by the Motion Encoder System.
The cart masses were approximately the same (see table). The total kinetic energy of the two-cart system changed by more than a factor of four. The total momentum was essentially unchanged, as expected, because the spring force was internal to the system.
Total kinetic energy
Velocity before (m/s)
Momentum before (kg m/s)
Kinetic energy before (J)
Velocity after (m/s)
Momentum after (kg m/s)
Kinetic energy after (J)
* Plain cart mass: 0.3198 kg
† Plunger cart mass: 0.3245 kg
In addition to studying superelastic collisions, have students use the Dynamics Cart and Track System to investigate various kinds of collisions, including elastic collisions using magnets as a nearly energy lossless bumper, lossy inelastic collisions using a spring plunger, and totally inelastic collisions using hook-and-pile tabs.
Derrick E. Boucher; American Journal of Physics. 2015, 83, 948–951.
Those of you who use Motion Detectors frequently, especially for studying free-falling objects, may find this article enlightening. It is a detailed study of how the horizontal position of the object relative to the Motion Detector can introduce an error in measured accelerations. The errors can make the measured accelerations slightly high.
Workshop Physics and Related Curricula: A 25‑Year History of Collaborative Learning Enhanced by Computer Tools for Observation and Analysis
Priscilla W. Laws; Maxine C. Willis; and David R. Sokoloff; The Physics Teacher. 2015, 53, 401–406.
This article describes the 25-year history of development of Workshop Physics and RealTime Physics and their influence on physics education around the world. We are proud to have worked with the authors for all of those 25 years.
The Atwood Machine Revisited Using Smartphones
Martín Monteiro; Cecilia Stari; Cecilia Cabeza; Arturo C. Marti; The Physics Teacher. 2015, 53, 373–374.
A smartphone is used to enhance a classic physics experiment. The phone is used as the weight on one side of an Atwood machine, and it also measures the acceleration. Our Graphical Analysis app is used to graph and analyze the data. The authors demonstrate that you can nicely show a linear relationship between the mass difference and vertical acceleration.
Turn Your Smartphone into a Science Laboratory
Rebecca Vieyra; Chrystian Vieyra; Philippe Jeanjacquot; Arturo Marti; and Martín Monteiro; The Science Teacher. 2015, 82, 32–39.
This article explains how to use the accelerometers in your smartphone to do a number of great physics experiments, including measuring the acceleration due to gravity, studying acceleration in an elevator, or measuring centripetal acceleration on a turntable. The best way to analyze the data collected this way is to use our Graphical Analysis for iOS or Android. Both apps are free downloads.
What unique, creative, and interesting solutions do you think your students could devise when presented with this challenge?
Your challenge is to design and build a sensor-controlled watering system for a potted houseplant using your EV3 robotics kit. Your device should automatically water the plant when the soil is too dry but also stop when the soil is sufficiently wet. You will use a Vernier Soil Moisture Sensor to monitor the moisture level of your plant’s soil. The soil will be considered “too dry” when the moisture level falls below 20%, and sufficiently “wet” when the moisture level rises above 28%.
The programming and constructing of a sample solution for this challenge are clearly outlined in the teacher’s section of our Vernier Engineering Projects with LEGO® MINDSTORMS® Education EV3 lab book. In our sample solution, we attach a LEGO® pneumatic pump to a LEGO® motor. A clear plastic water bottle is equipped with a 2-hole stopper, and tubing attaches from the bottle to the pump and from the bottle to the plant. We program this robot using a MINDSTORMS® Loop block that continuously monitors the reading from the Soil Moisture Sensor. If the reading is within the range, the robot does nothing; but if it falls below the threshold value, the program activates the motor to pump air into the bottle and push water out to the plant. The program waits to allow the water to percolate and loops back to monitor the sensor reading again.
When presenting this challenge to your students, one option is to share some, or all, of the sample solution with them. Another option is to have your students fully take on the challenge by allowing them to come up with their own distinct solution. This will undoubtedly lead to some truly imaginative, interesting, and fun ways to transport, carry, or splash water on a thirsty plant. For students who finish early or who want to pursue an independent project, the book also provides project extension ideas. In one project extension, a robot monitors the amount of light that the plant receives. If the light is too low, the robot must increase the light or warn the plant owner.
A real-world challenge like this introduces your students to the engineering design process. Students learn about robotics and programming, delve deeper into scientific principles, discover how sensors work, and learn how to solve problems as a team.
By Tom Smith, Engineering Educational Technology Specialist
The Truss Tester Accessory for the Vernier Structures & Materials Tester makes testing single trusses quick and efficient. Testing trusses can be a great engineering design project by itself, or you can use it as a building block for designing a bridge or another structure that is comprised of trusses.
I’ve been reading and thinking about trusses a lot lately, but I decided to get my nose out of the books and collect some of my own data. I took my construction skills out of the picture as much as possible and used the corner brackets that ship with the Truss Tester. These are also available for download as a 3D printer file. These brackets really make truss construction a breeze! I simply slid them on the bottom beam of the truss, anchored them in place with a small brad, and cut the rafters to length. I hot glued the rafters together at the peak, although the truss holder tended to keep those parts together during the test. I ended up making five different angles of simple triangular trusses, ranging from 34 to 53 degrees, all with a 21 cm base. I tested each truss, noted the maximum force required for it to fail, and plotted this data.
My data indicate that there is an optimum angle—not too steep and not too shallow. I also observed that most of my trusses seemed to buckle rather than pull apart or push together. In my next redesign, I started with a 40 degree truss angle and added some mid-rafter supports.
Scientists engaged in research are also often engineers. Consider the engineering that went into developing your lab equipment, such as your force sensor and auto-titration equipment.
Are you interested in helping your students take on an engineering activity such as automating a titration? You’ll find this activity among our Engineering Extension Activities. The automated titrator described in the extension activity monitors the pH of an acidic solution as a base is added via a standard buret. A Digital Control Unit is programmed in Logger Pro to activate a Servo Motor that opens the valve on a buret at low pH values. Once the acid is neutralized, it closes the buret. This feedback loop can be fine tuned to adjust for a different target pH, among other considerations.
A similar, more advanced project is mentioned in the “Vernier in the Chemistry Journals” section. Famularo, Kholod, and Kosenkov published an article in the Journal of Chemistry Education in which they describe a recent project in an upper-level instrumental analysis lab class where students created their own automated titrator devices. The article describes how the students built their own automated titration system using Vernier pH Sensors, Arduino microcontrollers, and off-the-shelf solenoid valves. In the end, they succeeded not only in building an automated titrator but also at controlling it over the Internet!
At Vernier, we applaud efforts like this that help students understand how our sensors and equipment work. When students look under the hood of their laboratory instrumentation and learn what makes something tick, they gain a better understanding of both the science they are investigating and the tools they are using.
Yeast are very important microorganisms that have been used by human cultures for centuries. Over time, humans have had a hand in yeast evolution through artificial selection while developing different strains of yeast for a range of functions, including baking and brewing. You can use our CO2 Gas Sensor to perform the “Evolution of Yeast” activity in Investigating Biology through Inquiry as a simple way to demonstrate the result of evolution due to artificial selection.
Flinn Scientific, Inc. has made it even easier to conduct this investigation by offering a guided inquiry kit, “The Evolution of Yeast with a CO2 Gas Sensor” (Flinn Catalog No. FB2128). The kit, which contains enough materials for 30 students in an inquiry setting, includes three strains of yeast and four different sugars, enabling students to study how different yeast strains process various types of sugar. Aligned to NGSS, this kit, along with Vernier technology, will help engage your students in scientific exploration.
We frequently talk with teachers who wonder if they should invest in a spectrophotometer or if they can run an experiment successfully with the more affordable Colorimeter. Let’s compare the two devices to clarify these options.
A spectrophotometer can be set to measure % transmittance or absorbance over a wide range of wavelengths. For example, the wavelength range of the SpectroVis Plus Spectrophotometer is 380 nm to 950 nm, and the wavelength interval is approximately 1 nm between reported values. In comparison, the Vernier Colorimeter can measure % transmittance and absorbance at four specifc wavelengths (430, 470, 565, and 635 nm) produced by internal LEDs.
Many of the same experiments will produce valid results on either device. For example, if you are doing an experiment based on Beer’s law (absorbance vs. concentration), both devices will give you a direct relationship between the absorbance value and the concentration of the standard solutions. Subsequent determination of the concentration of an unknown solution, based on the standards, will produce similar results.
Deciding to purchase a colorimeter or a spectrophotometer depends on the types of experiments in your curriculum. A spectrophotometer is compatible with all the spectroscopy experiments in the Vernier chemistry lab books. Several of those same experiments include instructions for use with a colorimeter. Many of the AP* chemistry lab experiments from the College Board emphasize the importance of a spectrophotometer’s ability to measure a full absorbance or % transmittance spectrum.
Kelly Mandy of Marist School in Atlanta, Georgia, was the 2015 recipient of the NABT Ecology/Environmental Science Teaching Award. This award, sponsored by Vernier, was presented at the 2015 NABT Professional Development Conference in Providence, RI. Mrs. Mandy is a seventh grade science, environmental science, and ninth grade biology teacher who uses the outdoors as an extension of her classroom. Each week, her students perform water quality tests in nearby Nancy Creek and submit results to Georgia Adopt-a-Stream, making the students directly involved in the monitoring of Georgia’s waterways. Mrs. Mandy’s students also design projects based on the work completed by her previous classes, which allows students to contribute in a short period of time to large-scale projects like the clearing of invasive Chinese Privet from Nancy Creek.
The NABT Ecology/Environmental Science Teaching Award is given to a secondary school teacher who has successfully developed and demonstrated an innovative approach in the teaching of ecology/environmental science and has carried his/her commitment to the environment into the community. Our sponsorship of this award includes $500 toward travel to the NABT Conference and $1,000 of Vernier equipment. The recipient also receives a recognition plaque and one year of complimentary membership to NABT. The application deadline for the Ecology/Environmental Science Teaching Award is March 15 of each year. While it has just passed for 2016, start thinking about applying in 2017. Applications will be available after the NABT Conference in November.