Video-based Problems in Experimental Physics (ViPEr Physics)
The transition from school physics to lectures in experimental mechanics and electrodynamics courses is attended by an erratic and necessary increase of requirements on students´ structural, conceptual and mathematical understanding of physical content.
Therefore a part of traditional problems in mechanics and electrodynamics recitation are replaced by video-based problems of equal content and level of difficulty. Problems of this new format are a sequence of linked theoretical and video based experimental tasks. Experimental tasks are related to data acquision and analysis in video recorded real experiments (video experiments) with suited programs on computers or tablet-computers.
The project ViPEr Physics focus on design and empirical study of the inherent additional value „theory-experiment interplay“ in video-based problems. In particular for novices it is difficult to gain learning effects from the theory-experiment interplay in lectures, because of too many changes between theoretical talk and experimental demonstrations, high information density and only passive learning activities (listening, observing). In recitations students have a greater scope development as in lectures (e. g. self-study, team work) to understand physical content from theory-experiment interplay.
- Development of video-based problems for recitations in experimental physics at universities - especially problems about challenging themes or with model experiments and context from nature, technique and everyday life
- Theory-experiment interplay as a principle to construct video-based problems
- Empirical research about the learning efficiency of theory-experiment interplay to foster mental construction of physical structures and conceptual understanding
- Theoretical media-centered foundation of video-based problems among the framework of problem based learning
- Implementation of video-based problems in recitations of experimental physics courses at the University of Kaiserslautern
Video analysis programs allow to conduct series of measurements of two dimensional kinematical quantities as well as single measurements of coordinates, time intervals, distances, angles and deduced average angular and linear velocities. Additionally the integration of computer-based measurement with sensors among the media format video allows to measure nearly all physical quantities like forces, temperatures, voltages, currents, … . Analysis and comparison of measured and theoretical data are possible with analysis tools like diagrams, regression, representations of vectors, theoretical graphs, … . Generally it is possible to establish video experiment in all physical subjects and to apply video-based problems in recitations to all experimental physics courses.
Shot from moving toy train (mechanics):
A ball is shot from a moving toy train:
a) Which preconditions are fulfilled, that the ball is falling back into the shot apparatus?
b) Describe qualitatively the trajectory of the ball seen from a passenger on the locomotive and seen from a person on the railroad embankment. Control the results by measurement of trajectories.
c) Derive formulas for time and width of flight and control them experimentally.
Left: Trajectory in fixed and moved frame of reference according to subtask b). Right: Determination of vx and vy(0) with linear regression of x(t) and vy(t). Formulas for calculation of initial velocity and angle.
Induction caused by change of area (electrodynamics):
A rectangle conductor loop (number of turns n = 1, width b = 4 cm) is pulled out of an spatial limited magnetic field:
a) Specialize in justified steps the general integral form of law of induction on the case shown in the experiment.
b) Explain the constant voltage.
c) Determine the flux density B.
1. Categorization of video problems by their added value compared to traditional problems [Gröber et al 2014a]:
- Theorie-experiment interplay: All video-based problems are a sequence of linked theoretical and video-based experimental tasks.
- Multiple representations: To solve video-based problems the predominantly representation forms laws and formulas are extended by the work with diagrams and in vector arrows in video analysis programs
- Experimental embedding of contexts: Video-based model experiments (with experimental equipment) and context experiments (without experimental equipment) built a bridge between physics and contexts like technique, nature and everyday life
2. Identification of manifold forms of theorie-experiment interplay (e.g. explaining differences between theory and experiment qualitatively or quantitatively) [Gröber et al 2014a].
3. Instructional design guide for structured production of video-based problems with minimal effort of time and work.
- Gröber, S., Klein, P. & Kuhn, J. (2014). Video-based problems in introductory mechanics physics courses. European Journal of Physics (EJP), 35, 5, 055019.**
- Klein, P., Kuhn, J., Müller, A. & Gröber, S. (2013). Video analysis exercises in regular introductory mechanics physics courses: Effects of conventional methods and possibilities of mobile devices. In Kauertz, A., Ludwig, H., Müller, A., Pretsch, J. & Schnotz, W. (Eds.). Multiple Perspectives on Teaching and Learning. (accepted)
Post doctorate: Ph. D. Sebastian Gröber (groeber(at)rhrk.uni-kl.de)