Role of the Movie Maker program in Physics experiments

Transcription

1 Role of the Movie Maker program in Physics experiments Cătălin ChiŃu 1,, Cătălin Măciucă, Ştefan Antohe 1 (1) University of Bucharest, Faculty of Physics, P.O.Box. MG-11, Bucharest, Romania () Energetic High School, Campina, Romania catalinchitumail@yahoo.com Abstract To be considered, a physical phenomenon can be reproduced in the laboratory. This process depends on many variables that make him the distinction in certain circumstances. Recording the experiment with webcam, especially when it involves the existence of mechanical movements, is important to help the analysis and interpretation of data acquired. This study presents the role of software computer programs Media Smart Webcam and Movie Maker to observe physical phenomena, to processing the film captures and interpretation of experimental data respectively. It is analyzing a real oscillation phenomenon to elastic oscillator. We appreciate the contribution made by using one computer during the training that is beneficial to increase the quality of the experiment and correctness of the interpretations in Physics discipline. Keywords: Laboratory experiments, Movie Maker program, Oscillation phenomenon, Physics discipline. Introduction Windows Movie Maker is video creating/editing software, included in Microsoft Windows Me, XP, and Vista. It contains features such as effects, transitions, titles/credits, audio track, timeline narration, and Auto Movie. New effects and transitions can be made and existing ones can be modified using XML code. Windows Movie Maker is also a basic audio track editing program. It can apply basic effects to audio tracks such as fade in or fade out. The audio tracks can then be exported in the form of a sound file instead of a video file ( The Windows Vista version of Windows Movie Maker support to importing video captures by webcam (video capture device) via Media Smart Webcam software program. This program stoked video-captures which are used to create the projects by Movie Maker program. Software is available to allow PC-connected cameras to watch for movement and sound, recording both when they are detected; these recordings can then be saved to the computer ( After capture, any clip can be dragged and dropped anywhere on the timeline. Once on the timeline, clips can be duplicated or split and any of the split sections deleted or copied using the standard Windows keyboard shortcuts or clicked and dragged to another position. Right-clicking any clip brings up the range of editing options. An Auto Movie feature offers predefined editing styles (titles, effects and transitions) for quickly creating movies (

2 The 5 th International Conference on Virtual Learning ICVL Edit video catches obtained during the laboratory experiment is, in some cases, very necessary. Thus, at certain times of the laboratory experiment, the evolutions of physical parameters deviate from the theoretical model accordingly. Therefore, to determine these parameters need to consider and analyze the parts of the phenomenon evolution which correspond and which verify the theoretical model. Experimenter will choose those portions of the video capture that meet these considerations. Deviations from the theoretical model will also be monitored and analyzed, providing interpretations of the limits of validity of that physical model. Training using video means necessary when certain phenomena and experiments are difficult to reproduced in laboratory conditions. Thus, after the video filming, these phenomena can be easily observed, analyzed and interpreted. In this way the teacher will choose and will edit those videos which are in accord with the objectives of the lesson (Malinovschi, 003). Can be determined, too, physical parameters which are impossible to measured in the absence of video capture. Considering that each student has a preferred learning style, training with video catches to experimental activities help students to develop video skills and digital skills. Training result in Physics discipline will be in accord with educational profile of students (Florian, 004; Gardner, 005; Gardner, 006, Miron 008). Training using the Movie Maker program can be completed using computer software. With them, users have to provide graphical interfaces (GUI) for the fast calculation of indirect experimental physical parameters. We estimate that this software is useful, too, to the evaluation studies of the efficiency of learning process. Theoretical contents Using to the physics lesson of audio and video files edited with Movie Maker program, enhance the quality of laboratory experiment. In this article we present stages of a publish project to the experimental theme: "The phenomenon of real oscillations. Elastic behaviour of an oscillator is analyzed in laboratory conditions. The article presents also the results obtained in laboratory experiment (A. V. SRL, 000). We made a video recording phase using a webcam, webcam with Media Smart software. Video Catches were stored in computer memory. For processing, the video file is accessed with the Windows Movie Maker - Vista version 6.0, using the button "IMPORT MEDIA. On computer screen will appear the project title and video capture imported (imported video file). Will select this file, and by the "drag and drop" method, the file is inserted in the "Timeline to begin its processing. When the video material is running, by pressing the "Split" button are cut sections of the project. Unnecessary sections will be eliminated using Remove" instruction. If the recording contains background noise, it can be eliminated by selecting the "Audio Levels" from the "Timeline". It will move the cursor to the right in this case. The operator can attach a sound comment to the video recording using the "Start narration" button. Also, using the "Import Media" button in the menu bar can be added to the project in progress, music videos and other files belonging. These files will appear on the home page of the project, and by the "drag and drop" method will attach them to the original file, in the following sections: "Video or "Audio / Music" of the editor ( Both the video and audio sequences can be attached to certain positions of the editing project.

3 16 University of Bucharest and University of Medicine and Pharmacy Târgu-Mureş After completing editing, audio video file must be saved. This is done by selecting the option "Publish Movie" from "File". At this point the operator has several options, depending on the chosen location to save the file created: Computers, DVD, Recordable CD, and digital video camera. After editing and saving the audio-video file, it can be used for educational purposes. Also, the whole project for editing audio and video file can be saved by selecting "Save Project" instruction from "File". Thus it will be possible to modify it later, depending on training requirements. Analysis of oscillatory phenomenon is based on the behaviour of small oscillations in laboratory conditions. Small oscillations phenomenon and the real oscillations phenomenon can be thoroughly studied using video. In the real oscillations phenomenon we have a friction force proportional and contrary to the direction of movement of the mass m of the oscillator. The friction force has the formula (Hristev, 1984; Yavorski, 1986): dy [1] F v = r = ry&, r = const dt The parameter r is called the proportionality constant of the friction force. By introducing the parameter named damping coefficient we obtained: [] r β = m dy [3] F = mβ = mβv dt This relationship shows that the amplitude of the damping oscillations decreases in time with the attenuation coefficientβ, according to the law: β t [4] A( t) = Ae Theoretically, this behaviour of the amplitude is an exponential decrease in time. The rate of decreasing in time of the damped oscillations amplitude is given by the dimension called logarithmic decrement of damping. The logarithmic decrement of damping (D) is defined by the natural logarithm of the ratio between the place at a period of time equal to the T period of elongations or the oscillation amplitude taking these oscillations (Hristev, 1984): y( t) A( t) [5] D = ln = ln = βt y( t+ T ) A( t+ T ) The formula of the energy of the really oscillator is: 1 β t = mω A = E0e = E0 [6] E e Energy is seen to exponentially decrease in time with the attenuation coefficient r β =. m Theoretically, the expression of the total energy at linear oscillator on elastic and gravitational fields is: k ( l+ A ) d ( n) ( n) [7] E( n) = + mg( A0 A( n) ) Using the energy sum up for the damped oscillatory motion made by the elastic oscillator, the following equation can be obtained: r t m

4 The 5 th International Conference on Virtual Learning ICVL E = E + W [8] i f dissipated The equation of the energy sum up will be the basis for the study of the free linear elastic oscillator. In fact, in the case of the real linear oscillations the variation of the total energy of the oscillator is equal to the mechanic work of the dissipative forces. The elastic constant measurement of the oscillator by a dynamic method means to take out the elastic pendulum from the equilibrium position. In this case an arbitrary number of complete oscillations are timed several times, writing down the paired values each time (Popescu et al., 006). The elastic dynamic constant of the spring is calculated for each case starting from the oscillator period in the situation of small oscillations: [9] T = t N = π m k d from which the value of the elastic constant is [5]: 4π mn [10] k d = t With Windows Movie Maker in Windows Vista 6.0 version, we edited the video capture file of the experiment. The oscillations occur with high frequency which does not allow direct measurement the data. However, analysis of video capture, sequence to sequence, made possible the extraction of experimental data. First, it was measured by the static method, the elastic constant of oscillator under conditions of static equilibrium (ks). The value of this parameter is required for the initial moment of the laboratory experiment. The dynamic elastic constant of oscillator was measured by dynamic experimental method. Certain parameters such as: variable amplitude of oscillations, duration of each set of oscillations, etc. are determined by the dynamics method. Consider mass m=40g. Video analysis allows for fine measurements: the period of oscillation, recovery times, and forces of inertia at the ends of elongations, movement speeds and accelerations (Panaiotu et al., 197). We determinate, using theoretical calculations, the total energies of oscillator and the dissipated energies by friction in the external environment. Experimental results This study characterized some of the physical parameters to real oscillations. A capture of screen about experimental measurement can be seeing in Figure 1. Figure 1. Screen capture from experimental work using edited file by Movie Maker program

5 18 University of Bucharest and University of Medicine and Pharmacy Târgu-Mureş The experimental data for representing the behaviours of the amplitude, the logarithmic decrement, energies and the dynamic elastic constant of real oscillator are in the Table 1. In this table, K S is the static elastic constant of the elastic oscillator. Table 1. The experimental data to real oscillations from elastic oscillator N A K (oscillations) S (N/m) 0 (cm) A (cm) t (s) 0,77,50 0,00 1,50 7, ,00 15,3 66 0,70, ,60 30,48, ,55 38, ,50 45, ,45 53, ,40 60, ,35 68,36 The measurement of the amplitude of the damped oscillations during teaching laboratory experiment, as a function of numerical groups of oscillations, shows an approximately exponential decrease of the amplitude (see Figure ) (A. V. SRL, 000; Origin Lab Corporation, 00). The evolution of the logarithmic decrement to the real elastic oscillator is presented in Figure 3. In this diagram it is applied fitting by a Boltzmann function. The evolution of the total energy to the real elastic oscillator is presented in Figure 4. In fact, with every oscillation, a part of the oscillator energy is dissipated outside as process energy (Popescu et al., 006). Figure. The evolution of the amplitude of oscillations Figure 3. The evolution of the logarithmic decrement of oscillations Figure 4. The evolution of the energy of the elastic oscillator In agreement with theory, the experimental graphic diagrams show a more pronounced decrease of the total energy of the real linear oscillator in comparison with the decrease of its amplitude during the time (Origin Lab Corporation, 00).

6 The 5 th International Conference on Virtual Learning ICVL The dissipative energy can be measured using the equation of balance energy. According to this value, the dissipative mechanic work is the result of the variation of the oscillator total energy for the initial and final states of oscillation (see Figure 5). In accordance with the graph from Figure 5, it can be seen that the rate of the energy dissipated outside by the linear elastic oscillator decreases with the increase of the number of oscillations. Decrease of the oscillator velocity correlates with the decrease in the dissipative force are contributes to the decrease of the dissipative energy exchange with the outside environment (Popescu et al., 006). The evolution of the dynamic elastic constant of the oscillator is presented in Figure 6. Figure 5. The evolution of the dissipative energy of the elastic oscillator Figure 6. The evolution of the dynamic elastic constant of the elastic oscillator The time dependent progress of the dynamic elastic constant shows its increase correlated with the increasing of the number of small oscillations (Figure 6). As the number of oscillations increased above 100 it is observed a slope change of dynamic elastic constant due to small plastic deformations of the elastic spring. Conclusions In cases when physical phenomena are difficult to be reproduced in laboratory conditions, the catches of image and sound are essential for understanding these phenomena. Using the files edited with Movie Maker program increases the number of physical parameters measured during teaching laboratory experiment. Are thus stimulated, knowledge transfer processes, directing the learning partners for scientific research. Also, training will increase efficiency, directing students learning by visual means. We estimate that programs use video and audio editing catches lead to useful projects to improve the quality of laboratory experiment. Students will be connected to those training activities that cover the entire spectrum of teaching-learning-assessment styles: visual, auditory and practical. References A. V. SRL. (000): Modul of Practical Laboratory Devices. Alfa Vega SRL, Satu Mare Florian, G. (004): Differentiated instruction to students in physics. Else Publishing, Craiova Gardner, H. (005): The Disciplined Mind. Sigma Publisher, Bucharest

7 0 University of Bucharest and University of Medicine and Pharmacy Târgu-Mureş Gardner, H. (006): Multiples Intelligences. Sigma Publisher, Bucharest Hristev, A. (1984): Mechanics and Acoustics. Didactic and Pedagogic Publishing House, Bucharest Malinovschi, V. (003): Teaching Physics. Didactic and Pedagogic Publishing House R.A., Bucharest Miron, C. (008): Teaching Physics. Bucharest University Publishing House, Bucharest Movie Maker, Panaiotu, L., Chelu, I., Petrescu-Prahova, M., Teodoru, E. A. (197): Experimental work in physics for high school. Didactic and Pedagogic Publishing House, Bucharest Popescu, M., Tomescu, V., Strazzaboschi, S., Sandu, M. (006): Physical-Manual 11th grade. LVS Crepuscul Publishing, Ploieşti Origin Lab - Corporation, (00): Scientific graphing and data analysis software products, Origin 7.0 Version. Massachusetts Webcam, Windows Movie Maker, Windows Vista, Yavorski, B., Detlaf, A. (1986): The Physical Dictionary. Mir Publishers, Moscow