What does an accelerometer measure? The obvious answer is acceleration, but that's not really true. An accelerometer actually measures normal force or restoring force which we equate to acceleration using the formula, F=ma. This article will explain the fundamental operating principles of accelerometers and investigate the capabilities and drawbacks of accelerometers in certain applications.
Let's create a game in Scratch that is controlled by a wireless controller using the PocketLab accelerometer. PocketLab can connect directly and wirelessly to Scratch, and can send sensor data in real time. This game uses the PocketLab accelerometer to move sprites around the screen.
This program is for intermediate or advanced Scratch users, and if you would like a simpler starting point to get started with connecting Scratch to the outside world through PocketLab, you can start here:
What Internet of Things projects are Stanford students developing? Stanford ME220 "Introduction to Sensors" is an introduction to the variety of sensors that are used in engineering practice. Students in this class get a comprehensive overview of common practices with sensors and learn the direction in which sensor technologies are heading.
Engage your students in engineering practices and classic force and motion and energy concepts in a fun and unique way. With a PocketLab attached to a Hot Wheels car and a track full of magnets, you'll be able to collect data on position, velocity, acceleration, and energy as your car zips up an over hills and around loops. Turn your students into theme park engineers and have them design "roller coaster" tracks, iterate on car designs for races, or teach basic concepts on position and velocity. This activity is sure to help engage your students in a meaningful way.
Carts constructed with the LEGO® Simple & Powered Machines Set are great for studying motion kinematics, as the resultant motion is fairly smooth, resulting in less noisy data. While you can use the range finder and PocketLab app, it has been found by the author that using Voyager and the VelocityLab app is less noisy as well. The problem that one immediately confronts when considering this approach, however, is that both the small wheels and the large wheels in the LEGO® set are too small for attaching Voyager.
A novel activity that demonstrates one of the effects of a microgravity environment. In this exercise, the structure of a flame is filmed while simultaneously plotting the acceleration of the system as it is released and experiences freefall. The apparatus is low-cost, possibly using only scrap materials found in the classroom. A PocketLab One is paired with a smartphone and used to collect the data. Conceptually, the exercise is straightforward, though considering noise in the data, limits of the system, and chemistry applications could easily enrich the content.
PocketLab sensors can measure the pressure in a fluid line easily, by putting the PocketLab into a plastic wash bottle. (For protection, put the sensor in a ziplock bag with a paper towel.) The wash bottle nozzle inserts easily into 1/4" ID tubing, and can be used as a pressure tap to measure fluid pressure in two different T junctions.
A thermoelectric generator (TEG) is a device that converts temperature differences directly into electrical energy. In the past several years, there has been a great deal of research in the use of TEGs to recover electrical energy from waste heat produced in a variety of systems. As a result of this research, the study of thermoelectric generators in physics and engineering curricula is well worth including in NGSS-based coursework.
The physics of the sounds produced by music boxes is definitely worth studying in curricula based upon NGSS (Next Generation Science Standards). The prongs of a metal music box comb and an oscillating meter stick that overhangs a table are both examples of cantilevers--long projecting beams that are supported only at one end. Other common examples include many suspension bridges, beams that support balconies on high rises, diving boards, airplane wings, and flagpoles mounted to the side of a building.