General equilibrium characteristics of a dual-lift helicopter system

The equilibrium characteristics of a dual-lift helicopter system are examined. The system consists of the cargo attached by cables to the endpoints of a spreader bar which is suspended by cables below two helicopters. Results are given for the orientation angles of the suspension system and its internal forces, and for the helicopter thrust vector requirements under general circumstances, including nonidentical helicopters, any accelerating or static equilibrium reference flight condition, any system heading relative to the flight direction, and any distribution of the load to the two helicopters. Optimum tether angles which minimize the sum of the required thrust magnitudes are also determined. The analysis does not consider the attitude degrees of freedom of the load and helicopters in detail, but assumes that these bodies are stable, and that their aerodynamic forces in equilibrium flight can be determined independently as functions of the reference trajectory. The ranges of these forces for sample helicopters and loads are examined and their effects on the equilibrium characteristics are given parametrically in the results

Pemindahan pembelajaran antara konsep dan aplikasi keseimbangan daya serta trigonometri dalam kalangan pelajar tingkatan empat

Previous studies indicated that students have minimal success rate in their learning transfer which involves physics concept application in everyday life. Therefore, a study was carried out to investigate learning transfer: (1) from the application o f trigonometry to the concept o f forces in equilibrium; and (2) from the concept o f forces in equilibrium to the application o f the concept. A survey method using tests was utilized to identify the relationships between each variable. Three testing instruments were constructed to determine the mastery level o f the application o f trigonometry (UTrigo), the concept o f forces in equilibrium (UKKD), and the application o f the conceptofforce in equilibrium (UAKD). A total number o f 60 Form Four Physics students who obtained As in Science and Mathematics in Peperiksaan Menengah Rendah (PMR) were chosen as the respondents. Then, 6 students were selected based on their test achievement to be interviewed in order to identify the difficulties o f the transfer o f learning. The percentage o f test scores were analyzed using Pearson correlation coefficients to identify the relationships between the variables. The interview data was analyzed using qualitative data analysis interactive model introduced by Miles and Huberman (1994). The findings o f this study showed that the students achievement level were moderate for the the concept offorces in equilibrium and applications o f trigonometry. While the level o f application o f the concept offorces in equilibrium in everyday life is at a weak level. The inferential analysis indicated that there is no relationship between the level o f application o f the concept o f trigonometry and the concept o f forces in equilibrium but there isa significant moderate correlation between the concept o f forces in equilibrium and the application o f the concept o f forces in equilibrium in everyday life. The analysis o f interview data showed that there are 11 categories o f difficulty o f transfer occured in UTrigo-UKKD and 12 categories o f difficulty o f transfer occured in UAKD-UKK

The Level of Mastering Forces in Equilibrium Topics by Thinking Skills

The aim of this research is to determine the level of mastering Forces in Equilibrium topics according to thinking skill for Form Four Physics students. 189 Form Four Physics students from secondary school at Kuala Kangsar district in Perak involved in this research. All students are 16 years old. Questionnaire method has been conducted in order to perform this research. Descriptive statistics namely mean and standard deviation has been used in this research. The findings showed the level of mastering Forces in Equilibrium topics according to thinking skills was unsatisfactory

The law of action and reaction for the effective force in a nonequilibrium colloidal system

We study a nonequilibrium Langevin many-body system containing two 'test' particles and many 'background' particles. The test particles are spatially confined by a harmonic potential, and the background particles are driven by an external driving force. Employing numerical simulations of the model, we formulate an effective description of the two test particles in a nonequilibrium steady state. In particular, we investigate several different definitions of the effective force acting between the test particles. We find that the law of action and reaction does not hold for the total mechanical force exerted by the background particles, but that it does hold for the thermodynamic force defined operationally on the basis of an idea used to extend the first law of thermodynamics to nonequilibrium steady states.Comment: 13 page

Studying the Effectiveness of Peer Instruction in Statics

This paper describes the peer instruction approach that was used in teaching Statics. The subject of Statics lays the foundation for subsequent courses, namely Dynamics and Mechanics of materials. Hence it becomes critical for any engineering student to understand and grasp the concepts of Statics course as it gives the students an ability to master follow-up material in upper level engineering courses. Therefore, improving learning in the subject of Engineering Statics deserves significant attention. Research shows that students who are actively engaged in learning, learn more. It was also proved that tradionally taught courses do little to improve student’s understanding of the key concepts and motivate only a few students in class. It is believed that peer instruction is an effective way to motivate students by making them teach their fellow students. This approach not only helps students learn core concepts and present it in technical language but also build their confidence. Results of this study indicated that post quiz scores improved for 71% of the students and 15% of students’ scores were 100 in both pre and post quizzes. The overall pass rate was 79% on quizzes and 79% on the final exam.Cockrell School of Engineerin