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Hands-on Experiment for Modeling the Baumgartner Jump Using Free-Fall Kinematics with Drag
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| Pengarang | : | - |
| Nama Majalah/Jurnal | : | The Physics Teacher |
| Volume / Edisi | : | 59 (No. 2) |
| Halaman | : | 111-113 |
| Abstrak | : | Supersonic free-fall jumps are excellent examples of kinematics in the context of drag. They have attracted a lot of media, public, and scientific interest. In 2012, Felix Baumgartner jumped from a height of approximately 38.969?km. During his flight he reached a top speed of 373?m/s, becoming the first human to travel faster than the speed of sound outside of an airplane. Since everyday topics are known to motivate students (e.g., Kuhn and Müller), the topic of Baumgartner’s jump seems to be very well suited for teaching kinematics in the context of drag. |
A Semester-Long Study of Magnetic Fields Using Smartphones to Engage Non-Physics Majors
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | The Physics Teacher |
| Volume / Edisi | : | 59 (No. 2) |
| Halaman | : | 108-110 |
| Abstrak | : | To help engage non-physics majors in a General Physics II (Electricity & Magnetism) course at the University of Indianapolis, students used their smartphones to detect magnetic fields on campus in a semester-long data collection project. This paper discusses details about the design of the project, previous studies that utilize smartphones for scientific data collection, the specific smartphone application that was used, an overview of findings, and future iterations of the project. |
From Pressure Maps and Wind Velocity to Northern Lights and Other Fascinating Phenomena on the Rotating Earth
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | The Physics Teacher |
| Volume / Edisi | : | 59 (No. 2) |
| Halaman | : | 103-107 |
| Abstrak | : | Owing to the presence of the Coriolis effect, the rotation of Earth has a multitude of surprising consequences that make the mechanics of the atmosphere or the oceans different from that of a fluid in a container. Since the Coriolis effect also captures the imagination of screenwriters, contributing to the continual exposure of students to bogus science, it is important to address these ideas in the physics classroom. This paper assumes that students are familiar with the Coriolis force acting on moving bodies in a rotating reference frame, and suggests a possible algebra-based approach. The information encoded in pressure maps is used to obtain wind velocity, and the result is applied in various contexts to learn about tilting sea surfaces, northern lights, and fluids flowing around phantom obstacles. |
6TiSCH: Industrial Performance for IPv6 Internet-of-Things Networks
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | Proceedings of the IEEE |
| Volume / Edisi | : | 107 (No. 6) |
| Halaman | : | 1153-1165 |
| Abstrak | : | The convergence of operational and information technologies in the industry requires a new generation of IP-compliant communication protocols that can meet the industrial performance requirements while facilitating the integration with novel web-based supervisory control and data acquisition (SCADA) systems. For more than a decade, the industry has relied on time-slotted channel hopping (TSCH) communication technology to meet these performance requirements through standards such as WirelessHART and ISA100.11a. TSCH-based networks have proven to yield over 99.999% end-to-end reliability, supporting flow isolation and QoS management while ensuring over a decade of battery lifetime. However, these technologies were designed to address the factory use cases of a decade ago, not considering IP compliance or standardized network management and resource orchestration as a must. The Internet Engineering Task Force (IETF) and the 6TiSCH working group (WG) have been actively working on this challenge by designing protocols to bridge the performance of industrial solutions with IP-compliant networks. The effort has resulted in 6TiSCH, a set of specifications that define the IPv6 control plane to manage and orchestrate a TSCH network. 6TiSCH provides the missing elements for zero-configuration TSCH network bootstrap, efficient network access authentication, and distributed and modular scheduling mechanisms. As a cross-layer effort, 6TiSCH leverages and integrates other IETF specifications and the WG has also driven the definition of novel specifications in other IETF WGs. An ultimate goal of this effort is the definition of a fully functional architecture where a combination of IETF protocols enables the envisioned convergence on top of the IEEE industrial standard. This paper introduces the work done by the 6TiSCH WG at IETF, evaluates the performance of the reference implementation, and discusses the 6TiSCH software ecosystem. |
Revisiting Standing Waves on a Circular Path
| Pengarang | : | Peter Riggs |
| Nama Majalah/Jurnal | : | The Physics Teacher |
| Volume / Edisi | : | 59 (No. 2) |
| Halaman | : | 100-102 |
| Abstrak | : | There are plenty of contributions in the physics literature on the subject of standing waves. What seems to be missing is an accessible, quantitative account of standing waves on a circular path at a level appropriate for undergraduate physics courses. In order to rectify this absence, a straightforward, concise, mathematical description of standing waves on a circular path is presented in terms of standard circular motion parameters. |
One Hundred Years Later, Introductory Labs Are Poised for Change
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | The Physics Teacher |
| Volume / Edisi | : | 59 (No. 2) |
| Halaman | : | 97-99 |
| Abstrak | : | Introductory lab courses have been a staple of the physics curriculum for over 100 years. Yet these courses are now poised for change as recent research shows that they do not meet a frequent goal of enhancing student understanding of lecture content. In thinking about how to move forward, a look back at experiment courses in history seems wise. Here, I take a quick look at our historical record and describe three interesting experiment courses from different time periods: Adolphe Ganot’s demonstration-style experiment course of the mid-1800s, Fredrich Kohlrausch’s research-grade experiment course in the late 1800s, and Newton Henry Black’s concept-exercise experiment course of the early 1900s. In looking back at these three courses, I find that instructors throughout history have had to face the same questions we do today. Specifically, what is the role of the introductory lab course in teaching experimental or theoretical concepts, and how much preparation, instruction, authenticity, and complexity are required? It seems that even if the introductory lab course is poised for change, that change may not be meaningful unless we answer these questions. |
The Central Scientific Company and its Apparatus
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | The Physics Teacher |
| Volume / Edisi | : | 59 (No. 2) |
| Halaman | : | 94-96 |
| Abstrak | : | Look along the shelves holding your laboratory apparatus and into the demo-prep room, and you will find apparatus by “Cenco” and “The Central Scientific Company” sharing space with your new PASCO equipment. At the 1989 AAPT meeting in San Luis Obispo I was asked to talk about Cenco in honor of one of its long-term employers and innovators, Paul E. Klopsteg, and I was hard put to limit my talk to the allotted 55 minutes. (It was one of our best meetings ever, and many wished that there were openings for us at the California Polytechnic State University!) In this article I want to remember the company and the apparatus that it made and sold. |
Extending Accurate Time Distribution and Timeliness Capabilities Over the Air to Enable Future Wireless Industrial Automation Systems
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | Proceedings of the IEEE |
| Volume / Edisi | : | 107 (No. 6) |
| Halaman | : | 1132-1152 |
| Abstrak | : | Many industrial automation systems rely on time-synchronized (and timely) communication among sensing, computing, and actuating devices. Advances in Ethernet enabled by time-sensitive networking (TSN) standards, being developed by the IEEE 802.1 TSN Task Group, are significantly improving time synchronization as well as worst case latencies. Next-generation industrial systems are expected to leverage advances in distributed time coordinated computing and wireless communications to enable greater levels of automation, efficiency, and flexibility. Significant progress has been made in extending accurate time synchronization over the air (e.g., 802.1AS profile for IEEE 802.11/Wi-Fi). Given the inherently unreliable, varying capacity and latency prone characteristics associated with wireless communications, proving the feasibility of worst case latency performance over the wireless medium is a major research challenge. More specifically, understanding what levels of capacity, reliability, and latency could be guaranteed over wireless links with high reliability are important research questions to guide the development of new radios, protocols, and time coordinated applications. This paper provides an overview of the potential applications, requirements, and unique research challenges to extend TSN capabilities over wireless. The paper also describes advances in wireless technologies (e.g., next-generation 802.11 and 5G standards) toward achieving reliable and accurate time distribution and timeliness capabilities. It also provides a classification of wireless applications and a reference architecture for enabling the integration of wired and wireless TSN capabilities in future industrial automation systems. |
Energy Cubes
| Pengarang | : | Amy D. Robertson |
| Nama Majalah/Jurnal | : | The Physics Teacher |
| Volume / Edisi | : | 59 (No. 2) |
| Halaman | : | 89-93 |
| Abstrak | : | The Next Generation Science Standards lay out a model of energy that locates energy within objects and fields, and tracks energy as it transfers between these objects and transforms between forms of energy while always being conserved. This model of energy pervades much of modern science and represents a foundational, cross-cutting concept for students. However, because it is abstract, energy is a very difficult topic for most students to learn. We have developed Energy Cubes to help make energy more concrete for students. Energy Cubes allow groups of learners to represent the dynamic energy changes in real-world scenarios by moving and flipping cubes on a horizontal shared workspace (see Fig. 1.) While Energy Cubes are accessible for elementary students, with carefully chosen scenarios we have found that Energy Cubes promote sophisticated and rigorous reasoning and argumentation among learners at all grade levels. The rules of Energy Cubes are presented in Fig. 2. |
Surface Currents on the Plates of a Charging Capacitor
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | The Physics Teacher |
| Volume / Edisi | : | 59 (No. 2) |
| Halaman | : | 86-88 |
| Abstrak | : | Ampère’s law is presented in introductory physics as a relation between the line integral of the magnetic field around a closed loop and the net current crossing any open surface spanning that loop. By allowing the surface to pass between the plates of a charging parallel-plate capacitor, Maxwell realized that this law is incomplete and introduced a term called the displacement current Id (due to changing electric flux), which needs to be combined with the conduction current Ic (due to charge flow) to give the effective net current I. Textbooks state that the way these currents are to be combined is by simple addition, I = Ic+Id. They verify that the resulting Ampère-Maxwell law gives the correct expression for the magnetic field at an arbitrary point outside of both plates for two different choices of spanning surfaces. However, those traditional two surfaces are special and do not prove that the total current must be the simple addition of the displacement and conduction currents. A third, more general spanning surface is used here to establish it. This third approach draws attention to the surface currents on the capacitor plates. |