New Compadre Portal collection resources

Boston University Physics Easy Java Simulation: Free Body Diagrams

Wed, 22 May 2013 11:05:58 EST

This simulation offers users the opportunity to sketch free-body diagrams relating to a one-dimensional situation. Two boxes are stacked one atop the other. The bottom box rests on the floor of an elevator, which may be at rest, moving with constant velocity, or accelerating. The task for the user is to sketch free-body diagrams for the top box, the bottom box, and the two-box system. This applet was created with EJS, Easy Java Simulations, a modeling tool that allows users without formal programming experience to generate computer models and simulations.

NVT-Molecular Dynamics Model

Sun, 19 May 2013 18:33:32 EST

The NVT-Molecular Dynamics Model performs molecular dynamics simulations at constant temperature of 32, 108, 256 or 500 molecules interacting through the Lennard-Jones potential, in a wide range of densities and temperatures covering liquid, vapor and solid states. Thermodynamic properties, radial and speed distribution functions, velocity autocorrelation functions (vcf's) and their Fourier spectra, and mean square displacements (msd's) are calculated and displayed. Self-diffusion coefficients are worked out from the vcf's and msd's. Self space-time correlation functions (sstcf's) are estimated and compared with the Gaussian approximation. The 3D molecular motions can also be visualized. The motion equations are integrated by two methods, at user's choice: the damped-force with leap-frog Verlet's algorithm, and the "ad-hoc" rescaling with the velocity Verlet algorithm. The model allows to assess the role of the potential cut-off distance, the number of steps in equilibration runs, the time-step and the gap between time origins for vcf's, msd's and sstcf's. The NVT-Molecular Dynamics Model was developed using the Easy Java Simulations (EJS) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the jar file will run the program if Java is installed. You can modify this simulation if you have EJS installed by right-clicking within the map and selecting "Open Ejs Model" from the pop-up menu item.

Instantaneous Frequency Stock Market Model

Fri, 17 May 2013 09:42:02 EST

The Instantaneous Frequency Stock Model estimates a stock's cyclical fluctuations over a three-day period to determine how fast the market is moving. The instantaneous frequency of an input signal is calculated by modeling an input function's most recent data points as a sin wave and performing a Fourier transform to derive the function's frequency. This model implements different velocity indicators on daily closing prices of a few common companies, and allows the user to compare values of the indicators at different times. The Instantaneous Frequency model was developed by Matt Mohorn using the Easy Java Simulations (EJS) modeling tool. You can examine and modify the physical model for this simulation if you have Ejs installed by right-clicking within the plot and selecting "Open Ejs Model" from the pop-up menu.

Intermediate Mechanics Tutorials: Simple Harmonic Motion

Thu, 16 May 2013 16:11:40 EST

This set of tutorial materials covers the topic of simple harmonic motion. Students examine qualitatively and quantitatively the motion of a simple harmonic oscillator, as exemplified by a mass attached to an ideal spring. There are two tutorials, one using motion graphs and one using vectors, to describe the motion. Students analyze and solve the differential equations of motion to develop an understanding of the physical parameters in the problem. This material also includes a pretest, example homework, and test questions. This is part of a large collection of similar tutorial materials in intermediate classical mechanics.

NEED Project: Intermediate Energy Infobook

Tue, 14 May 2013 13:46:32 EST

This free infobook for Grades 6-8 provides an overview of energy sources, with special focus on the transformations necessary to convert energy into usable fuels for consumption. It takes a look at biomass, fossil fuels, hydropower, geothermal, solar, wind, and nuclear energy in a context of environmental concerns and climate change. Each chapter goes into detail on the discovery and production of each resource, environmental impacts, costs to process and transport, and availability for consumption. High-quality reproducible graphics accompany all segments, providing illustrations of power plants, extraction, mining, electricity generation, and country-by-country fuel usage. The sequence is part of the NEED K-12 curriculum, in which energy forms are extensively studied in the elementary grades to build foundations for understanding the physics behind energy transformations and the Law of Conservation of Energy. The NEED Project is a national initiative to bring innovative curriculum materials in energy education to teachers and learners from the primary grades through college.

NEED Project: Energy from the Wind

Mon, 13 May 2013 07:10:16 EST

This resource for Grades 7-9 provides turn-key lessons for teaching a two-week unit on the use of wind energy to generate electricity. The first week is a study of the history and science underlying wind energy; the second week features an engineering design project for students to build their own windmill blades. In the culminating activity, students take on various community roles to decide where to locate a wind farm. This resource includes every component required for immediate classroom use: lesson plans, illustrated lab procedures, pre and post-test assessments, age-appropriate background information, worksheets, graphics for classroom projection, and student guidebooks. The NEED Project is a national initiative to bring innovative curriculum materials in energy education to teachers and learners from the primary grades through college. Note: The windmill blade design activity requires purchase of a kit costing $450.00. All other activities can be performed using materials easily acquired from hardware stores or science supply houses.

NEED Project: Energy of Moving Water

Fri, 10 May 2013 13:22:13 EST

This resource for middle school provides 13 complete lessons for teaching about hydropower and conversion of moving water to electrical energy. The unit crosses the curriculum to include physical science, engineering design, earth systems, language arts, social studies and math. As with all NEED educational materials, this resource includes every component required for immediate classroom use: lesson plans, illustrated lab procedures, rubric, pre and post-test assessments, age-appropriate background information, worksheets, graphics for classroom projection, and student guidebooks. Specific physical science objectives revolve around energy transformation, energy flow in systems, kinetic vs. potential energy, gravitational potential energy, magnetic field, and electromagnets. Each investigation requires students to first read about the topic in "infobooks" (included in the materials), then make predictions, complete the lab, record data, and write a conclusion. The NEED Project is a national initiative to bring innovative curriculum materials in energy education to teachers and learners from the primary grades through co

NEED Project: Science of Energy

Thu, 09 May 2013 17:21:41 EST

This is a curriculum unit for middle school designed to introduce energy as a physics concept in five class sessions. It meets multiple NextGen Science standards through hands-on lab stations. Students investigate energy transfer, storage of energy, the difference between "energy forms" and "energy sources", and trace energy flow through systems. Creative activities include "Happy Sphere, Sad Sphere" for exploring kinetic vs. potential energy; solar panels and glow toys to learn about transformation of radiant energy; "Memory Metal" (nitinol wire) to explore how thermal energy is transformed into motion; and light sticks to investigate chemical energy transformation. Each activity includes Teachers Guide, background information, detailed lesson plans, glossary, and example assessments. A full set of materials can be purchased from NEED or easily obtained through science supply retailers. The NEED Project is a national initiative to bring innovative curriculum materials in energy education to teachers and learners from the primary grades through college.

Intermediate Mechanics Tutorials: Newton's laws and velocity-dependent forces

Thu, 09 May 2013 16:05:34 EST

This set of tutorial materials covers the topic of velocity dependent forces. Students examine qualitatively and quantitatively the motion of objects being acted upon by a velocity dependent force, exemplified by the motion of objects experiencing air resistance. Students analyze and solve the equations of motion to develop an understanding of the physical parameters in the problem. This material includes a tutorial, pretest, homework, test questions, and instructor notes. This is part of a large collection of tutorial materials in intermediate classical mechanics.

Exploring Student Understanding of Atoms and Radiation with the Atom Builder Simulator

Wed, 08 May 2013 17:14:55 EST

Learning about radiation requires understanding the general structure of atoms, but many college physics students do not have such understandings. In our efforts to develop inquiry based materials on radiation, we have accumulated additional evidence showing that certain students do indeed have substantial difficulties understanding the basic structure and properties of atoms, and that these difficulties impair their understandings of the simplest radiation processes—emission and ionization. This paper reports on our investigations of student difficulties in understanding basic properties of atoms and ionization and radioactivity. We also describe results from a class using a new pedagogical simulator—the Atom Builder—and provide evidence for marked improvement in student understanding.

Students' and Instructor's Impressions of Ill-structured Capstone Projects in an Advanced Electronics Lab

Wed, 08 May 2013 16:56:40 EST

During spring 2010 six students enrolled in an advanced electronics lab worked in pairs on ill-structured capstone projects. They designed electronic circuitry to automate experiments that were completed in a previous advanced physics lab. Some ill-structured features of these capstone projects included open-ended goals, limited guidance from the instructor and the possibility of multiple solution paths. Semi-structured interviews were conducted with both the students and the instructor of the class, before and after the students worked on these ill-structured capstone projects to gauge the participants' expectations of the projects before they began and their views about these projects after they were completed. We report on the pre- and post-project impressions of the students and instructors regarding this ill-structured learning experience.

Is Inquiry-Based Instruction Good for Elementary Teaching Majors? The Effects on Chemistry Content Knowledge and Views About Teaching and Learning Science

Wed, 08 May 2013 16:29:39 EST

Although science educators have advocated that elementary teaching majors learn science concepts using inquiry-based methods, many college professors believe that these courses are merely “watered down” versions of traditional lecture-based courses. This study compared the chemistry content knowledge of elementary teaching majors enrolled in an inquiry-based course and science majors enrolled in traditional lecture-based courses. It also compared the elementary teaching majors' views of how science is taught and learned to the views of secondary science teaching majors. The elementary teaching majors developed chemistry content knowledge comparable to the students enrolled in the traditional lecture-based course, but they developed views regarding how science is taught and learned that were more in line with the constructivist ideals than the secondary science teaching majors. The elementary teaching majors also improved their interest and confidence in teaching science in the elementary school setting. These results suggest that both sets of teaching majors would benefit more from inquiry-based science courses than lecture-based courses.

Investigation and Evaluation of a Physics Tutorial Center

Wed, 08 May 2013 16:22:36 EST

The Physics Resource Center (PRC) is a tutorial center offering supplemental instruction to all introductory level physics students. Physics students were surveyed to investigate and evaluate the center's effectiveness in meeting their needs. Survey results and suggestions offered by the students are reported. Findings include the dependence of PRC attendance on factors including gender, course performance, and social engagement.

Avoiding Reflex Responses: Strategies for Revealing Students' Conceptual Understanding in Biology

Wed, 08 May 2013 16:18:27 EST

There is widespread concern about the level of scientific literacy in the U. S. An important, although often overlooked, point, is that student learning is generally only a good as the assessments used to measure it. Unfortunately, most assessments measure recall and recognition rather than conceptual understanding, and as a result over-estimate levels of scientific literacy. We have encountered this fact during the construction of the Biology Concept Inventory (BCI). Using the concept of diffusion, which is taught in a wide range of introductory biology, chemistry, and physics courses, as an exemplar, we describe lessons learned and strategies we use to create questions that better probe student understanding.

Female physicist doctoral experiences

Tue, 07 May 2013 13:52:29 EST

The underrepresentation of women in physics doctorate programs and in tenured academic positions indicates a need to evaluate what may influence their career choice and persistence. This qualitative paper examines eleven females in physics doctoral programs and professional science positions in order to provide a more thorough understanding of why and how women make career choices based on aspects both inside and outside of school and their subsequent interaction. Results indicate that female physicists experience conflict in achieving balance within their graduate school experiences and personal lives and that this then influences their view of their future careers and possible career choices. Female physicists report both early and long-term support outside of school by family, and later departmental support, as being essential to their persistence within the field. A greater focus on informal and out-of-school science activities for females, especially those that involve family members, early in life may help influence their entrance into a physics career later in life. Departmental support, through advisers, mentors, peers, and women’s support groups, with a focus on work-life balance can help females to complete graduate school and persist into an academic career.

Nanoreisen: Adventures Beyond the Decimal

Wed, 01 May 2013 11:50:16 EST

This website provides an interactive exploration of the physics of microscopic systems, from the scale of a centimeter to the structure of the atomic nucleus. Three example "nano-journeys" are provided into a human cell, a light-emitting diode, and a computer memory chip. Each stage of a journey explores structures a factor of 10 smaller than the previous stage. High-resolution digital photography, scanning electron microscopy, and computer animations are used to depict the structures at the various levels. The website also provides background information at each level about the physics, engineering, and biology of the structures studied. The size of the structures at each level are compared to a meter by analogy with the relative sizes of the Earth and common objects.

A Student's Guide to Global Climate Change

Tue, 30 Apr 2013 22:04:07 EST

The Environmental Protection Agency website provides an overview of climate change for students. It includes the sections Learn the Basics, See the Impact, Think like a Scientist, and Be Part of the Solution. Text and colorful illustrations and graphs present the ideas.

Ice over the Poles

Mon, 29 Apr 2013 16:48:45 EST

This Earth Observatory webpage provides a description of how global warming will affect sea ice and precipitation. Also, the text describes the “positive feedback” through which melting of ice sheets or glaciers can increase the rate of global warming. This webpage is part of NASA's large Earth Observatory collection of features, images, global maps, and news items.

Greenhouse Effect

Mon, 29 Apr 2013 14:21:22 EST

This HyperPhysics webpage contains information and diagrams on global warming, the greenhouse effect, and greenhouse gases. Numerous graphs and diagrams illustrate the measurements and concepts. Also, this page displays the famous "Keeling curve" showing atmospheric carbon dioxide concentration versus time from 1958 to 2004. This page page is part of the HyperPhysics Collection, which contains many short, illustrated pages on various areas of physics and astronomy.

NASA Finds Thickest Parts of Arctic Ice Cap Melting Faster

Sun, 28 Apr 2013 21:51:35 EST

This interactive NASA webpage displays images of Arctic ice in 1980 and 2012. To facilitate comparison, the visitor can sweep a vertical line from left to right to reveal all of one image or all of the other. Text provides information about the rate of loss of ice and how it is defined.