Concept Of Force Research Articles

Paramilitary Forces, Domestic Politics and Conflict: A Case of the Sudan Crisis.

What is the threat posed by paramilitary groups on the state? This paper seeks to examine the role and impact of paramilitary forces on domestic politics and how their involvement results in political (in)stability. It examines how the interplay between the Rapid Support Forces, a paramilitary force in Sudan and the Sudan Armed Forces has resulted in a humanitarian crisis since the overthrow of Omar Al Bashir's government in 2019. The authors argue that the formation of paramilitary groups is aimed at protecting the government from internal and external threats, yet these paramilitary groups can shift or withdraw their loyalty to the political leadership. Such a shift the paper finds creates a high potential for confrontation between the paramilitary forces and regular forces leaving the citizens vulnerable to mass atrocities and war crimes. The paper begins by examining the origin, spread and activities of militia groups globally and at the regional level before examining the concept of paramilitary forces. The authors then look at Sudan’s historical and contemporary experiences with paramilitary groups before discussing the recent crisis between the regular forces and the paramilitary force in Sudan. They find that the preferential treatment of paramilitary forces influences their actions during a crisis.

The development of the concept of exchange forces in the 1930s: close encounters between Europe and Japan and the birth of nuclear theory

The development of the concept of exchange forces in the 1930s: close encounters between Europe and Japan and the birth of nuclear theory

Sub-global equilibrium method for identification of elastic parameters based on digital image correlation results

In this work, a new, simple method is presented, which enables identification of material properties of solids basing on the digital image correlation (DIC) measurements. It may be considered as a simplified alternative of low computational complexity for the well-known finite element model updating (FEMU) method and virtual fields method (VFM). The idea of the introduced sub-global equilibrium (SGE) method is to utilize the fundamental concept and definition of internal forces and its equilibrium with appropriate set of external forces. This makes the method universal for the use in the description of a great variety of continua. The objective function is the measure of imbalance, namely the sum of squares of residua of equilibrium equations of external forces and internal forces determined for finite-sized part of the sample. It is then minimized with the use of the Nelder–Mead downhill simplex algorithm. The efficiency of the proposed SGE method is shown for two types of materials: 310 S austenitic steel and carbon-fiber-reinforced polymer (CFRP). The proposed method was also verified based on FE analysis showing error estimation.

Acceleration inside an aircraft in parabolic flight

This paper aims to present and analyse the acceleration data inside an aircraft during a parabolic flight. The data used were obtained during the flight from the automatic recordings of the aircraft and from a portable data logger with a built-in 3-axis accelerometer connected to a graphic calculator. There is good agreement between the accelerations obtained by the two methods. Based on the altitude data collected during each parabolic manoeuvre performed by the aircraft, it was possible to estimate the gravity of Mars and the Moon, as well as the values of the acceleration of gravity during the moments of microgravity. The analysis presented can also help to improve the understanding of the concepts of inertial forces and the equivalence between gravity and acceleration.

Identifikasi Etnosains Pada Kerajinan Anyaman Okomama Dengan Pewarna Alami Tanaman Nila Di Desa Noesiu

Ethnoscience is an approach to science learning that implements local wisdom (regional culture) using certain cultural products. Local wisdom can be in the form of food and drink, traditional ceremonies, dances, games, traditional language and traditional weaving. One of the traditional woven based local wisdom is okomama. Traditional woven okomomama made from palm leaves using indigo plants as a natural dye for motifs and color patterns. The purpose of this study is to explore physical concepts in the process of okoma weaving. The research method used is qualitative descriptive research in the form of interviews, field observations and documentation. The research data was analyzed in several stages, namely data reduction, display data and conclusions. This study aims to identify physics objects and concepts that can be found in genius-based local science learning. The results of the study obtained that in the process of making natural dyes in ocomoma matting there are physical concepts identified in the concepts of frictional force, material strength, load distribution, pressure, work, energy, temperature, heat, absorption, reflection of light, and change of form.

Assessment of preservice physics teachers’ knowledge of student understanding of force and motion

In physics education, a number of studies have developed assessments of teachers’ knowledge of student understanding (KSU) of specific physics concepts with modified versions of existing concept inventories, in which teachers were asked to predict the popular incorrect answers from students. The results provide useful but indirect information to make inferences about teachers’ knowledge of the misconceptions that students may be using in answering the questions. To improve the assessment of teachers’ KSU, a new instrument is developed using a three-tier item design. The items were adapted from 17 questions from the Force Concept Inventory on force and motion. Each item was designed in three tiers, with tier 1 asking for teachers’ own answers to the question to test their content knowledge, tier 2 asking for teachers’ predictions of popular students’ incorrect answers, and tier 3 asking for teachers’ explanations of students’ incorrect answers in an open-ended form. The three-tier design captures teachers’ content knowledge, predictions, and explanations in a single item to allow explicit measures of teachers’ own content knowledge and their KSU on students’ misconceptions. The instrument was validated with preservice physics teachers, who were master-level graduate students in a normal university in China. The assessment results also suggest that the preservice teachers’ KSU of force and motion was only moderately developed, and their content knowledge was uncorrelated with their KSU. In addition, a four-level progression scale of KSU was also developed, which categorized the preservice teachers into five proficiency groups. Published by the American Physical Society 2024

Misconceptions of High School Students on Motion and Force Using the Force Concept Inventory (FCI)

This research aims to identify high school students' misconceptions regarding motion and force using the Force Concept Inventory (FCI) instrument. This study used a quantitative method with respondents of 108 students in class XI science. Misconception data was obtained using FCI in the form of multiple-choice questions. There are 30 questions with five options. The results showed that a total of 46 out of 108 students (19.44%) answered 8 to 11 questions correctly, 41 students (37.96%) answered 5 to 7 questions correctly and the other 21 students (42.59%) only answered 2 to 4 questions correctly. The conclusion is students had misconceptions about the concepts of motion and force, especially on topics such as kinematics, Newton's laws, the principle of superposition, and kinds of force. This research implies the importance of understanding students' misconceptions in developing physics curricula and learning strategies in high schools. It is hoped that the research results can provide information to teachers about students' conceptual understanding so that appropriate learning strategies can be developed to correct students' misconceptions in learning.

Pengembangan Alat Peraga Motor Listrik Sederhana Pada Materi Gaya Lorentz

An experiment has been carried out on the application of the Lorentz force to a simple electric motor to study the direction of the magnetic force. This research aims to determine the change in electrical energy into mechanical energy, in which the Lorentz force is the force that arises due to the presence of an electric current in a magnetic field. So, if we have a conducting object that is in a magnetic field, then we flow it with an electric current, a force will arise that can move the object. The benefit of applying the Lorentz force is that in an electric motor, by passing an electric current through a coil in a magnetic field, a Lorentz force can be generated in the form of rotation in the electric motor to move the shaft which can then be used for all your daily needs. Tools that use the Lorentz force principle in everyday life are fans, multimeters and dynamos. The development of a simple electric motor teaching aid has been carried out as a means of learning the Lorentz force concept for students. This teaching aid is designed to illustrate the basic principles of electric motors, where the Lorentz force plays a role in moving the coil in a magnetic field. This research aims to increase students' understanding of the Lorentz force and its application in electric motors. Development methods include tool design, prototyping, and testing on students. The trial results showed an increase in students' understanding of the Lorentz force concept after using this teaching aid. It is hoped that the development of this simple electric motor teaching aid can be an effective alternative in learning physics, especially in understanding the concept of Lorentz force.

Measuring critical force in sport climbers: a validation study of the 4 min all-out test on finger flexors

PurposeThe critical force (CF) concept, differentiating steady and non-steady state conditions, extends the critical power paradigm for sport climbing. This study aimed to validate CF for finger flexors derived from the 4 min all-out test as a boundary for the highest sustainable work intensity in sport climbers.MethodsTwelve participants underwent multiple laboratory visits. Initially, they performed the 4 min intermittent contraction all-out test for CF determination. Subsequent verification visits involved finger-flexor contractions at various intensities, including CF, CF −2 kg, CF −4 kg, and CF −6 kg, lasting for 720 s or until failure, while monitoring muscle-oxygen dynamics of forearm muscles.ResultsCF, determined from the mean force of last three contractions, was measured at 20.1 ± 5.7 kg, while the end-force at 16.8 ± 5.2 kg. In the verification trials, the mean time to failure at CF was 440 ± 140 s, with only one participant completing the 720 s task. When the load was continuously lowered (−2 kg, −4 kg, and −6 kg), a greater number of participants (38%, 69%, and 92%, respectively) successfully completed the 720 s task. Changes of muscle-oxygen dynamics showed a high variability and could not clearly distinguish between exhaustive and non-exhaustive trials.ConclusionsCF, based on the mean force of the last three contractions, failed to reliably predict the highest sustainable work rate. In contrast, determining CF as the end-force of the last three contractions exhibited a stronger link to sustainable work. Caution is advised in interpreting forearm muscle-oxygen dynamics, lacking sensitivity for nuanced metabolic responses during climbing-related tasks.

Matriser, krafter och fysik: Elevers levda erfarenheter av bedömningsmatriser i grundskolans fysikundervisning

Over the past decade, the use of rubrics for formative purposes in science education has attracted attention for its potential to positively influence students’ self-regulation and learning. This study explores students’ lived experiences of using rubrics as part of learning about the concept of force in the physics classroom. To address these experiences, 19 compulsory school students were interviewed about their use of a rubric specifically designed for an assignment on force and motion. Three main themes emerged from an analysis of the descriptions of their lived experiences: (i) rubrics provide a sense of control; (ii) rubrics are required for high grades, but create stress; and (iii) rubrics foster strategic learning. The experiences revealed in these themes have the potential to deepen our understanding of the challenges involved in using rubrics to teach physics and have implications for teaching students about force.

Persistence of Conceptual Errors in First-Year University Physics Course and Its Possible Relationship with Learning Styles

In this work, we study the persistence of some fundamental previous ideas in physics in a group of freshmen at the Universidad Politécnica de Madrid (Spain). For this purpose, we analyze the answers to a questionnaire consisted of 24 multiple-choice items, most of them borrowed from the Force Concept Inventory (FCI). Our study is performed in two different ways by using, on the one hand, classical test theory and, on the other hand, the Pearson product–moment correlation. The survivance of some of the previous ideas at the end of the course is assessed by comparing and critically analyzing the answers of the students to the same test at the beginning and the end of the term. A possible connection with Honey–Alonso learning styles (LS) is also discussed. The results yielded by our study demonstrate the persistence of some of the initial and previous ideas, no matter the students’ previous qualifications or their current LS.

Exploring gender differences in the Force Concept Inventory using a random effects meta-analysis of international studies

The Force Concept Inventory (FCI) is one of the research-based assessments established by the physics education research community to measure students’ understanding of Newtonian mechanics. Former works have often recorded the notion of gendered mean FCI scores favoring male students notably in the North American (NA) based studies. Nevertheless, these performance gaps remain inconclusive and unexplored outside the NA context. This paper aims to fill this gap by meta-analyzing the mean FCI scores between gender based on the existing physics education research literature internationally. We analyzed the magnitude and direction on the mean FCI scores between gender based on primary international studies published over the last two decades. We also explored the moderating impact of international study characteristics on the meta-analytic findings by performing a subgroup analysis to study the different study regions stratified by two subgroups (NA vs non-NA authors). Thirty-eight studies reporting the mean FCI scores by gender were included in the present meta-analysis. We employed Hedges’ g statistic to estimate to what degree the mean FCI scores may be different between male and female students on each study. Under a random effects model, we meta-analyzed the findings and conducted a subgroup analysis to answer the research questions. In summary, our meta-analysis indicated a significantly positive and moderate amount of gendered mean FCI scores in favor of male students both in NA- and non-NA based regions, and the performance gaps were wider in the NA-based studies. Suggestions are discussed while interpreting the mean FCI scores between gender for teaching, learning, and forthcoming studies. Published by the American Physical Society 2024

Engineering Professors' Conceptions on the Conceptual Field of Electrostatics in Mexico

This study explores the conceptual understanding of electromagnetism among physics professors at the Aeronautical University in Querétaro, Mexico. While student misconceptions in electromagnetism have been extensively studied, research on professors' understanding and its potential impact remains limited (Pardhan & Bano, 2001). This research aims to address this gap by focusing on the core concepts of electrostatic force, electric field, and electric potential. Eight professors participated in the study. Their academic background, electromagnetism course history, and teaching experience were documented. A three-tier diagnostic test, based on Vergnaud's theory of conceptual fields, was then used to assess their conceptualisation of these concepts and their interrelationships. The analysis revealed that only one professor consistently demonstrated correct understanding across all three concepts. Interestingly, this professor was also the one with the most extensive teaching experience in the subject. The results suggest a potential connection between teaching experience and a deeper conceptual understanding of electromagnetism. Further research is needed to explore this connection and its implications for mitigating student misconceptions through effective teaching practices.

Methodological suggestions for creating subquestions for the Force Concept Inventory (and other research-based assessments)

The Force Concept Inventory (FCI) is a research-based assessment that is used internationally to assess student understanding of Newtonian mechanics. The assessment has been investigated from a number of perspectives and many suggestions have been made for its improvement. One suggestion is the creation of subquestions. Subquestions are a tool to reduce false positives (answering a survey item correctly without correct understanding) and false negatives (answering incorrectly despite correct understanding). In this presentation, we will discuss how we created subquestions for two items on the FCI, informed by survey-based interviews with students and the original intended targets of the items. Our research aims are not only to present the subquestions we developed, but to share our methodology of creating these subquestions, as this methodology can be used in general for producing subquestions on other research-based assessments as well.

Concept of Force Representations of Prospective Primary Teachers

The representation of physics concepts is essential to support teaching/learning in primary school. Investigating how future teachers represent the physical concepts has great importance. Research was carried out on concepts of force representations of 274 prospective teachers, enrolled in the Primary Education Sciences degrees. Rubrics were designed and used to analyse different dimensions involved in drawing, descriptions, didactic and disciplinary motivations. It emerged that most of the representations do not include the representation of the involved forces, but rather implies a precise didactic approach to the force concept.

가상자산의 物件性 여부 및 물권법 법리에의 포섭 가능성에 관한 논의

Whether virtual assets can be regarded as a ‘thing’ or ‘property has been widely discussed, because it can be a prerequisite to whether legal theories in property law and in bankruptcy law would be applied to virtual assets. Although financial regulatory Acts on virtual asset law are being legislated around the world, few countries have legislated how virtual assets will be understood in civil law. In this situation, Liechtenstein has in 2019 and Switzerland has in 2021 partially regulated civil legal issues of virtual assets in their Acts and UNIDROIT adopted its principles on digital assets in 2023. Liechtenstein’s TVTG(Token- und VT-Dienstleister-Gesetz) does not recognize virtual assets (tokens) as a thing, but restricts the concept and legal effects of tokens only within the Act. The Act distinguishes between de facto powers of disposition and justified right of disposition, but a person who has de facto power over a VT-key is considered to have legitimate right over the tokens associated with that key. In addition the disposal of tokens does not depend on the existence of a legal title (principle of abstraction), while the so-called causality principle prevails in Liechtenstein property law. If a token is disposed of without a legal title or if an initially existing legal title later ceases to exist, the legal transaction must be rescinded ex-nunc in accordance with the law of unjust enrichment. Considering the characteristics that the VT-system fulfills the registration function and has a high level of reliability, the possibility of acquisition in good faith is recognized. A significant part on civil legal issues in the DLT(Distributed Ledger Technologie) Act of Switzerland relates to ‘register uncertificated security’ (Registerwertrecht) which dematerializes securities using distributed ledger technology. The Swiss legislators additionally reviewed whether cryptocurrency could be considered a thing and concluded that it is unreasonable to extend the concept of natural forces to cryptocurrencies such as Bitcoin and that legal status on the blockchain can be claimed only to the participants in the blockchain system. Considering that cryptocurrency is not recognized as movable property, it is recognized as a type of intangible property. However, the Act recognized the right to separation for crypto-assets in general. This provision is enacted because it was practically necessary to determine whether crypto-assets belong to the bankruptcy estate when the wallet provider goes bankrupt. The DLT Act does not recognize general crypto-assets as a thing, but the right to separation of crypto-assets is recognized under certain conditions. The UNIDROIT Principles treat digital assets as being susceptible to being the subject of proprietary rights, without addressing whether they are considered ‘property’ under the other law of a State. The Principles don’t prescribe the specific requirements for a valid right of ownership in a digital asset or for it’s valid transfer. Instead, the principles provide a detailed definition of control, which assumes a role that is a functional equivalent to that of ‘possession’ of movables. However, ‘possession’ in this context is a purely factual matter and not a legal concept. But the concept of control serves as a necessary requirement for qualifying for protection as an innocent acquirer of a digital asset and as a method of third-party effectiveness and a basis of priority of security rights in a digital asset. It should be noted that a security right in a digital asset that is made effective against third parties by control has priority over a security right in the digital asset that is made effective against third parties only by a method other than control. A proprietary right in the digital asset remains effective on insolvency, but difficulties are expected if the insolvent person might refuse to reveal the password. In conclusion considering the char

The evolution of physics: from the action of forces to the power of action

At the beginning of the study of physical phenomena, the idea of "force" was widely used to explain the non-stationarity of observed phenomena, such as the movement of bodies. However, as mechanics and physical theories developed, the force notions gained own formal definitions and names, without the use of the term "force". So, the concept of kinetic energy arose instead of "vis viva", and "current" instead of "current strength" ets. Additionally, a number of new physical theories have been formulated without the use of force concept. As a result, different types of forces have gradually been replaced by other more important concepts, such as energy and action, which are closely linked to fundamental physical principles. It is interesting to note that the general trend in the development of civilizations has been a shift from unrestricted power (expressed in the thesis "might makes right") to its subordination and incorporation into a legal framework. This is similar to the evolution of physics, which has seen the notion of force become eliminated or subordinated to more general principles and laws.

ЭНЕРГЕТИЧЕСКИЕ СВОЙСТВА СИММЕТРИЧНЫХ ДЕФОРМИРУЕМЫХ СИСТЕМ

Energy methods for calculating structures, which have become popular for a century, are based on the Lagrange principle and have the meaning of equality of work of external forces and internal forces. Having proved their effectiveness in the overwhelming majority of problems of structural mechanics, they became the dominant approach in formulating the problems of studying solid deformable systems and gave rise to the main methodology for solving problems. As a result, a situation has arisen that the internal potential energy of a deformed body remains insufficiently studied.
 The paper develops an approach to the study of the symmetric structure at critical levels of strain energy. The criterion of critical levels of strain energy, based on the concepts of "self-stress" ("self-balance") of a deformable body. Limiting values of the structure strain energy may get by varying the reactions and deflections in the nodal points. The extreme values of forces and displacements of the rods are calculated in matrix form from the values of nodal reactions (displacements).
 Methodology for studying the energy properties of a system is shown on the examples of the study of symmetric rod systems without involving the concept of external forces. The technique is based on matrix methods of structural mechanics and the mathematical apparatus of eigenvalue problems. The comparison of structural design and structural analysis solution of structural mechanics tasks by traditional methods and with the proposed methodology is carried out.

Misconceptions of Intermolecular Forces in General Chemistry Courses

The misconception is the most topic in chemistry learning that is important to analyze. There are many advantages for lecturers and students to know about misconceptions. This research aims to describe misconceptions in general chemistry courses, especially intermolecular forces (IMFs) topic. The two-tier multiple-choice tests have played an important role in helping researchers determine students’ level of understanding and in identifying specific misconceptions. The project used a convenience sample of 88 students (76 female and 12 male) chemistry education program that studied IMFs as participants. Misconception knew from the test’s second tier, which is the student’s reason for the answer. Surprisingly, 29 misconceptions were acquired from the test about IMFs concepts. This needs to be a special concern for lecturers of basic chemistry courses in order to evaluate the learning process that has been carried out. Students misconceptions in basic chemistry courses will have an impact on organic chemistry courses because the concept of intermolecular forces will be studied in depth in organic chemistry courses. The success of students in organic chemistry courses is highly dependent on the initial knowledge of students, especially in basic chemistry courses

Basics of post Newtonian gravity- a new simpler approach

Galileo studied bodies falling under gravity and Tycho Brahe made extensive astronomical observations which led Kepler to formulate his three famous laws of planetary motion. All these observations were of relative motion. This led Newton to propose his theory of gravity, which could just as well have been expressed in a form that does not involve the concept of force.