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Researches in physics education indicate that the limit process is an obstacle in understanding the concept of instantaneous speed by students in introductory courses of physics. Medieval authors, however, defined the concept without apparent use of a process of limit. Galileo Galilei explored the medieval ideas to state laws of motion for falling bodies. His methods inspire an alternative way to teach the concept of instantaneous speed. [ABSTRACT FROM AUTHOR]

This study aimed to compare the rally times, the pattern of complexes and actions performed between professional volleyball players and players under 19. Four matches were evaluated, one male and another female from the Brazilian Superleague (professional volleyball) and another from the Games of the Federal Institutes (under-19 school volleyball) using the Adobe®Premiere®Pro software, where the rally times and their intervals, % of density, the types and numbers of complexes and the actions in the rallies were analyzed, in addition to the point obtained in the rally. Under-19 school players and female volleyball players showed longer rally times and % of density, reducing recovery time. Under-19 school players held a greater number of complexes in the rally than the professionals. Complexes with 3 and 1 actions were the most performed and showed the highest occurrence of points. Under-19 school players revealed a higher occurrence of points through fundamental errors (blocking, defense, and attack), whereas there were more points of attack in professional games. Serve errors in the men's super league were more relevant than in the other categories. In conclusion, under-19 school players differ from professional players in rally times, complexes, and action patterns, due to less proficiency in the sport. [ABSTRACT FROM AUTHOR]

The shortening of hamstring muscles leads to alterations that interfere with the harmony of the kinetic movements being essential to maintain the flexibility. The Total Motion Release® technique decreases the postural imbalances, promoting the flexibility gain. The purpose of this study was to evaluate the gain and long-term maintenance of flexibility of the hamstrings muscles in female university students of the Physiotherapy course of the State University of Goiás, submitted to the Total Motion Release® (TMR) technique. It was an experimental, randomized, and longitudinal-prospective study. It was performed with female university students who have been characterized by an anamnesis record. The level of physical activity was assessed by the International Physical Activity Questionnaire -- Long Version (IPAQ). The functional tests applied for flexibility were: Active Knee Extension; and Finger-Soil Distance. The Analysis of the knee extension angle was performed by the CvMob® program. Groups A (control) and B (experimental) were evaluated in the pre-intervention; post-intervention and follow up 10 days after the final intervention. The sample consisted of 44 participants, the control group (n=22), with a mean age of 20.50, body mass 54.25, height 1.62, BMI 21.25 and the experimental group (n=22), with mean age 21.95, body mass 57.04, height 1.62, BMI 21.81. In the intergroup comparison there were significant differences after four sessions in the Right Knee Active Extension (p=0,006), Left Knee Active Extension (p=0,046) and Finger-Soil Distance (p=0,020). The Total Motion Release® technique proved to be effective in the flexibility gain of the hamstring muscles at the end of four sessions, however it did not maintained the results at follow up after 10 days of its closure. [ABSTRACT FROM AUTHOR]

The article aims to analyze, through qualitative and quantitative processes, the audiovisual streaming of the first movement of Gustav Mahler's First Symphony performed by the Berlin Philharmonic Orchestra in 2019. The theoretical framework of reference is Baxter (2019), Tsivian (2018) and Salt (1974) whose proposals elucidate the instrumental described as asl (Average Shot Lenght). The methodology is qualitative analysis by description of behavior, and quantitative analysis by kinematics. As a result, the article brings reflections on the dynamization in kinematic terms of the audiovisual language of concerts for orchestra, suggesting some of the implications and eventual problems to be eventually discussed. [ABSTRACT FROM AUTHOR]

As a result of studies for interdisciplinary applications developed under a Master's Degree in Science Teaching, with the aim of orienting teachers and undergraduate students in Physics, Mathematics and related fields for innovative practices next to the student body, this study deals with the teaching of functions in classes of 9th grade of Elementary School, involving Mathematics and Physics, from the quasi-experimental delimitation of time series. By means of the videoanalysis of small kinematics experiments carried out by the students, using the free software Tracker, questions were treated about related and quadratic functions, derived from these experiments and observations, with pre-tests and conceptual tests of six double classes, intercalating the accomplishment of the physical experiments and the application of the tests. The videoanalysis of the kinematics experiments, with conclusions reached by the students, entered as an introductory factor and basis of the functions theme. The pre and post-tests were mediated by the active methodology of Peer Instruction and the exchange of understandings and experiences between the participating groups made possible the evaluation and measurement of the study regarding its effectiveness. The treatment was applied in three classes of a school of the Foundation of support to the Technical School of Rio de Janeiro, totalizing the participation of 76 students. The results of this research, obtained in the development of the activities, studied by the statistical analysis of Hake's normalized gain under the quasi-experimental design, indicate the possibility of using the proposed active methodology as potential mediator of the teaching-learning relationship in collaborative contexts. [ABSTRACT FROM AUTHOR]

In order to verify the kinematics graphs comprehension for a group of high school students, it is recommended to use an instrument that has a content valid by experts and a statistical validation. In this sense, was chosen the updated version of Test of Understanding Graphs in Kinematics (TUG-K), proposed in 2017 by Zavala and originally created by Beichner, in 1994. The TUG-K was elaborated to measure the understanding of graphs in kinematics of university students, mostly. Therefore, for this test to be used in basic education, it is necessary to know if it has statistical validity in this context. Consequently, a statistical analysis of the test was performed, after being applied at two different moments, with upper secondary level students of a federal school in Rio de Janeiro. The measured parameters were the same used by Zavala. The main result of this article was to demonstrate that TUG-K validity in this group. As a complement, it was shown that Hake's normalized learning gain from this group of students exposed to kinematics lectures was 17%, a value that is expected to be in traditional teaching. The underlying perspective is to disseminate and encourage the use of TUG-K in high school. [ABSTRACT FROM AUTHOR]

In this work, we will analyze the condition to a particle leave the contact with a vertical circular loop. This is a typical problem shows in textbooks of Physics, here we will present three different forms to solve it. For that, we will use only fundamental math concepts, it means without use differential calculus. We will show you that, although this analysis is been constructed in intuitive principles, it is equivalent to what is traditional show in textbooks. Overall we will discuss a special case, where a similar deduction of ours leave a false conclusion. [ABSTRACT FROM AUTHOR]

Physics is typically introduced to students through kinematics. In general, students learn to solve simple examples, for example, how to find the time of a journey from one position to another one. With the popularization of computer science, it is important to present problems which can be analyzed playfully on the computer. With this objective, through simulations, we study different strategies for the kinematics of a robot that must map a room. The efficiencies of the different strategies were compared by calculating some quantities from the trajectories, such as Convex Hull and Entropy. Comparing these quantities, it is possible to discuss the mapping performed by each one of them. [ABSTRACT FROM AUTHOR]

The swimming bench has been used as complementary training in swimming, however, there are no studies that analyze in three dimensions the specificity movement applied by this land-based swimming simulator. The aim of the study was to compare the stroke parameters of front-crawl swimming and swim-bench, as well as movement symmetry. Ten swimmers (16 ± 1.4 years) were filmed in a real swimming condition (50m) and a 30s swim bench stroke simulation using four GoPro Hero 4 cameras. Stroke dimensions, hand speed in the underwater phase and hip displacement were analyzed. Comparison between tests and sides symmetry was performed by two-way repeated measurements ANOVA and stroke rate between the tests was analyzed by Student's t-test. Swimmers showed a symmetrical characteristic in both conditions which indicates high body control and proficiency. The stroke dimensions differed between tests, mainly explained by the displacement limitation, trunk and hip rotation in the swim bench. The stroke rate and underwater hand speed pattern were similar (p> 0.05) and partially justify the use of this equipment as complementary land-based training, evaluation and control of the swimmers performance. [ABSTRACT FROM AUTHOR]

The present study had as objective to investigate the whole process of the shot of penalty in the technical and kinematic scope. This is a cross-sectional observational study of a qualitative and quantitative character, carried out with 6 aquatic athletes from Náutico Atlético Cearense, aged between 16 and 19 years of national level, through the capture of cinematographic images of each shot of penalty taken, for further analysis in DARTFISH 5.0 software, according to a standardized quantitative and qualitative technical performance data sheet. A black "overalls" was used whose shoulders, elbows and wrists were demarcated in the white color. Each one took five penalty shots. Statistical analysis of the data was done through the Graphpad Prism 3.0 programs, using mean and standard error of the mean, variance and ANOVA, followed by Tukey with graphical exposition. The players who achieved higher average velocities compared to the others, were the ones that obtained the least variations in the parameters, but only the height reached by the player's body under the surface of the water seems to be decisive in the efficiency and power of the penalty shot. [ABSTRACT FROM AUTHOR]

The association between contextual interference effect (CIE) and kinematic measures has been little investigated. The purpose of this study was to investigate the CIE on velocity and acceleration kinematic profiles of upper limb. Thirty-two subjects (23,7 ± 3,3 years) were assigned to groups of blocked practice (GPB) and random practice (GPA). The task consisted in achieve three targets in three specific sequences as quickly and accurately as possible. The study was designed in acquisition phase and transfer test. The variables of performance were reaction time, movement time and response time and the kinematic variables were peak of speed, relative time to peak of speed and number of peak acceleration points. The main findings showed that GPA showed lower movement time and response time than GPB. Regression analysis indicated that change in peak velocity during practice was associated to the change of the reaction time from practice to the transfer test. As peak velocity is a measure related to preprogramming, it is suggested that central control was essential to the CIE. [ABSTRACT FROM AUTHOR]

This paper presents an educational tool developed using the Arduino platform with a position sensor and the PLX-DAQ software, which was used in developing a learning experiment suitable for teaching graphics kinematics that was applied to the master's work. The aim was to overcome learning difficulties faced by students of basic education in the construction and interpretation of graphs, like position versus time in the Cartesian coordinate system. We present a detailed description of instrumentation and some results of an implementation carried out with two groups of 1st year of high school, a State school in the city of Candiota / RS. In the implementation, we identified an increase in student performance, which demonstrated certain difficulties in the analysis and interpretation of motion graphics at the beginning of the activity; however, they developed skills in the course of tasks, achieving both qualitative and quantitative results (statistically significant). The students were able to interpret and reproduce motion graphics in real time from the instrumentation proposed in this work. [ABSTRACT FROM AUTHOR]

The development of anthropomorphic prosthesis is an area of research that has attracted the attention of research centers worldwide. The application of knowledge in the robotics field has made increasingly intelligent devices. The robotic prostheses for lower limbs have a greater complexity because they can substantially influence the posture and mobility of its user. The mathematical tools used in the development of robots can be applied to the modeling of prosthesis and has great importance for the implementation of their control. This paper develops a mathematical model applied to a robotic foot prosthesis with 2 degrees of freedom. The Denavit- Hartenberg algorithm is a very effective tool in a representation where kinematic can extract various relationships that allow relating orientation and position. Ultrasound sensors can make the orientation of the foot with relation the ground. The human gait is also a major factor in the control of a robotic foot prosthesis and can be analyzed as standing behavior criterion. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to show to the basic university physics instructor and the high school teacher how we can solve interesting kinematic problems with the introduction of a typical pursuit problem. We can discuss this kind of problem in various situations ranging from military applications to applications related to game design. The pursuit of a merchant ship by a pirate ship was the problem chosen as an example. We also discuss a pedagogical approach to this problem, showing as an example how the teacher can simulate this kind of problem using the software Modellus. [ABSTRACT FROM AUTHOR]

The purpose of this study was to develop a growth curve model of young swimmers' performance and determinant factors during a competitive season. Fourteen boys (12.33 ± 0.65 years old) and 16 girls (11.15 ± 0.55) were evaluated. Their performance, stroke frequency, intracyclic speed fluctuation, propelling efficiency, active drag, coefficient of active drag and power to overcome drag were measured in four moments throughout the season. Growth curve modeling was used to understand the performance development and its determinant factors. A high inter and intra-variability was showed. In each evaluation moment, different determinant factors had a significant effect in the performance. The goodness-of-fit ranged between 1.40 ≤ x2/df ≤ 3.74 (good-reasonable). Growth curve modeling proved to be a comprehensive way to gather information about the performance development of young swimmers during a competitive season. [ABSTRACT FROM AUTHOR]

At university introductory physics courses, often problems are solved as a direct application of theory, as if they were exercises. In this paper we present evidence that students tend to solve problems in a superficial manner, without applying fundamental problem-solving strategies such as qualitative analysis or hypothesis making which prevents them from arriving at a correct solution. Using as a point of reference the solving of a problem that is usually regarded as an exercise, we propose some approaches that could serve as guidelines for problem-solving in Physics teaching, and stimulate reflection among students to find solutions, as well as use scientific procedures. [ABSTRACT FROM AUTHOR]

The aim of this study was to analyze the relationships between the angular kinematic pattern of head-out aquatic exercise sailor jigs" at increasing musical rhythm. Six young women with at least one year of experience conducting this type of head-out aquatic programs were evaluated. The exercise was recorded on video, in frontal plane, using two cameras for double projection at five music cadences (120 bpm, 135 bpm, 150 bpm, 165 bpm and 180 bpm). Images were then digitized in specific software (Ariel Performance Analysis Systems). Results have shown that, the cycle period decreased through the incremental protocol. No significant relationship was found between music rhythm and relative angle between thigh and trunk. In contrast, the relative angle between thigh and leg and between arm and forearm decrease with the music rhythm, at least for the left limb. In conclusion, it seems that there is a trend to decrease the angular displacement and unchanged the angular velocity when increasing rhythm at least in certain anatomical landmarks. [ABSTRACT FROM AUTHOR]

Technological advances in the last decades have demanded new ways of teaching at different levels. In this way, we present, analyze and discuss the possibilities in applying a proposal of didactic material that we developed to be used with students in the final years of elementary school II and high school. The material is composed of a virtual board game and software developed in Python that allows the organization and analysis of the game's data. The material, of a ludic and technological nature, allows study concepts related to the movement of an object, such as position, classification of its movement velocity. This study is executed through the analysis of the data generated by each student in the board game and plotted in graphs of position and velocity, both versus time. The platform is intuitive, relatively simple to use and shows the potential to contribute to the teaching process in a more meaningful context, allowing students to be more engaged and concreteness about the topic. [ABSTRACT FROM AUTHOR]