Inexpensive video analysis technology now enables students to make precise measurements of an object's position at incremental times during its motion. Such capability now allows users to examine, rather than simply assume, energy conservation in a variety of situations commonly discussed in introductory physics courses. This article describes the use of video analysis software in studying energy conservation for (1) objects in freefall, (2) simple pendulums, (3) objects rolling down inclines, and (4) masses oscillating on springs.

While computer technology continues to enhance the teaching and learning of all science disciplines, computer simulations, in particular, have become exceptionally beneficial in physics education. In addition to the manner in which physics instructors integrate computer simulations into their instructional practices, the design of a simulation may also determine its potential for influencing a student's conceptual development and understanding. This paper examines the effects of four differently designed simulations on students' predictions and subsequent understanding of how images are formed by converging lenses, specifically in relation to outcomes when portions of the lens or object are covered. Results indicated that differing numbers of rays depicted in the lens simulations had little effect on student predictions, but the origination point(s) of the rays did influence student predictions. Also reported is how minimal instructor scaffolding substantially influenced student use and value perceptions of the simulation.

In 2007, NREL and Xcel Energy collaborated on an analysis study to better understand the fuel displacement potential, the costs, and the emissions impacts of market introduction of plug-in hybrid electric vehicles (PHEVs) into the Xcel Energy Colorado Service Territory. The study indicated the potential for petroleum displacement and highlighted the value of vehicle charge management to limit costs and emissions impacts. As an extension and demonstration of the analysis results, a real-world fleet demonstration project was initiated. The purpose of the project was to 1) quantify the real-world fuel savings benefits of PHEVs, 2) gain an understanding of potential utility loading scenarios due to the introduction of PHEVs, and 3) develop and demonstrate the equipment and tools necessary for utility controlled charging. The project team successfully evaluated the performance of three vehicles placed in consumer service with charge control functions directed by Xcel Energy. Ten different charge control scenarios were explored, several of which correlated to the previous analysis study of 2007. Analysis of 16 weeks of field study data supports the conclusions drawn in the previous study. PHEV technology holds great promise for enabling petroleum reduction in transportation. Utility controlled charge management was demonstrated and potential load profiles were generated; some of which were synchronized with renewable resources and ancillary services suggesting that utility load management of PHEVs could provide both low CO 2

Because mathematical formulae and problem solving are such prominent components of most introductory physics courses, many students consider these courses to be nothing more than courses in applied mathematics. As a result, students often do not develop an acceptable understanding of the relationship between mathematics and science and of the role that mathematical modelling plays in science knowledge generation. This paper describes an instructional sequence on wave motion based on teaching through modelling that serves not only to build student understanding of wave characteristics, but also to demonstrate through multiple representations a primary relationship between science and mathematics. This lesson further demonstrates how model building can combine technology and pedagogy to strengthen student understanding of the scientific process.

An alternative conception for the observed differences in light bulb brightness was revealed during an unguided inquiry investigation in which prospective elementary teachers placed identical bulbs in series, parallel, and combination direct current circuits. Classroom observations, document analyses, and video and audio transcriptions led to the discovery of this alternative conception, appropriately christened 'Brightness Rules'. Assessments administered three weeks after the activity confirmed that several prospective teachers maintained the 'Brightness Rules' conception even after instructor-led intervention. Implications of the discovery of this alternative conception are discussed with respect to a previously administered assessment question that could not identify the presence of this alternative conception. The study US national standards call for the implementation of inquiry practices (National Research Council 1996) and the integration of technology into teaching and learning (NSTA, Rationale, ¶1). This report results from a study investigating the role of physical and computer-simulated resources when both were concurrently available for novice learners to use during unguided inquiry physics activities. The unguided inquiry activity described in this research was titled Light bulbs in series, parallel, and combination. Students were first directed to determine and explain what happened to the brightness of otherwise identical light bulbs in a dc circuit as more and more bulbs were (a) added in series, and (b) added in parallel, and then to explain how the relative brightness of multiple bulbs could be determined when they were connected in combination circuits. Physical equipment for each laboratory group included dry cells, snap-together cell holders, one switch, connecting wires, two digital multimeters, and at least twenty identical bulbs taken from Christmas tree light strands. Additional resources included the textbook, class notes, and a computer with access to a circuit simulation (www. physicslessons.com/exp22b.htm). Participants Fifty-one prospective teachers (45 females, 6 males) taking a conceptual physics course developed for middle-grade mathematics and science specialists served as participants in this study. Ranging in age from 18 to 36 years, the majority (88.2%) of participants were aged 18 to 21 years. Only 15 of the 51 students (29.4%) had taken no prior secondary or undergraduate physics course.