Dynamics Of Rotational Motion Research Articles

Research of the influence of the volumetric-mass layout of the aircraft on the dynamics of rotational motion in the longitudinal plane

In this paper, the influence of the volumetric-mass layout of the aircraft on the dynamics of rotational motion in the longitudinal plane is considered. The studies allow us to evaluate the relationship between the space-mass layout of the aircraft and the perturbing aerodynamic effects that occur during the transition process. The deviation of the empirical values of the aerodynamic moment from the linear dependence and the time of the transition process were considered to be quantitative estimates of the quality of the transient process. An original aerodynamic experiment with a moving aircraft model was proposed as a research method. The continuous change in the position of the aerodynamic model in the experiment made it possible to analyze the effects and their influence on the motion parameters in real time, and take into account the unsteadiness of the flow on the airframe surface. The conducted experiment shows that to reduce the time of the transient process, the value of the moment of inertia of the aircraft should be reduced but, in this case, the aerodynamic moments caused by the inertia of the medium and various unsteady flows will increase. As a result, when choosing the ratios of stability and controllability of an aircraft, one should pay attention not only to the geometric location of the center of mass and focus of the aircraft, but also to the mass-volume characteristics of the aircraft.

A Mathematical Model of Value Co-Creation Dynamics Using a Leverage Mechanism

Service marketing for sustainability can be addressed in studies on human wellbeing promoted by delight and value co-creation within service systems. However, there is scant research on formal models of value co-creation dynamics with respect to customer delight. This study aimed to formulate a mathematical model of value co-creation dynamics based on a “seesaw catapult” using a lever system. This is based on the concept presented in ISO/TS 24082 and involved service providers’ customer centricity and customers’ active participation. We solved the maximization problem for a ball’s height (i.e., customer experience) by optimizing customers’ active participation and the scale of data collection. Theoretical analysis of rotational motion dynamics revealed nonlinear, complementary, and trade-off relationships in the model. Optimal conditions for the variables were obtained, and additional conditions of the service provider’s customer centricity were derived to achieve customer delight. In this study, a switchback co-creation process of the service system was constructed based on these findings. This study contributes to the value co-creation literature by providing a normative model of co-creation dynamics that enables deductive development and generates various co-creation processes. Service marketing sustainability can be expanded by exploring appropriate co-creation scenarios that maintain and engage people in service systems.

A device for studying the laws of dynamics of rotational motion of solids

A device for studying the laws of dynamics of rotational motion of solids

Phase Control for the Dynamics of Connected Rotators

We study the dynamics of rotational motions in a system of two asymmetrically coupled pendulum-type systems, investigating the mechanisms of losing stability for in-phase rotational motion. We analyze the scenario where chaotic dynamics appears depending on the values of the control parameters.

Billiard Physics: Motion of a Cue Ball after Hit by a Cue Stick Horizontally

Billiards and pool games provide an excellent medium to discuss several physics principles including Newton’s laws of motion, friction, impulse-momentum theorem, work-energy theorem, kinematics and dynamics of rotational motion, and rolling motion. This paper provides a complete analysis of the motion of a cue ball that is given a sharp impulse, which is parallel to the horizontal surface. The horizontal impulse, in this work, is restricted to be in the plane passing through the ball’s center of mass and the contact point such that it sets the ball in horizontal motion with no sidespin. The motion of the cue ball until it eventually starts to roll without slipping is analyzed for all different impulse points on the surface of the ball. These analyses provide physics instructors a set of exciting examples on the rolling motion.

Dynamic method for controlling dynamic viscosity of liquid

The purpose and objectives of the work are to develop scientific and technical bases and experimental testing of the dynamic method of control of the dynamic viscosity of liquids located directly in the pipeline on the basis of angular accelerations of the body immersed in the liquid. The developed method of control of the dynamic viscosity of liquids allows to take into account the uneven supply of mechanical energy from the drive motor of the rotary viscometer based on the assessment of the dynamics of the motion of the body immersed in the liquid. The developed method of control of dynamic viscosity of liquids is based on the proven positions of theoretical mechanics, dynamics of rotational motion, the theory of machine parts and is a logical continuation of the development of rotational methods of control of viscosity of liquids. The results of experimental testing of the developed dynamic method of control of the dynamic viscosity of liquids suggest the adequacy of the developed approaches. As a result of experimental studies of motor oil G-Energy 10w-60 on the basis of the developed dynamic method revealed the ratio of dynamic viscosities at temperatures of 100 ° C and 40 ° C, which was 6,7. Application of existing methods of control of viscosity of G-Energy oil at temperatures of 100 ° C and 40 ° C gives the ratio of dynamic viscosities 6,8. The discrepancy between the results of the dynamic method of control of the dynamic viscosity of the liquid and the control results obtained by known methods of control of the dynamic viscosity of liquids is about 1%.

Analysis of Fan Waves in a Laboratory Model Simulating the Propagation of Shear Ruptures in Rocks

The fan-shaped mechanism of rotational motion transmission in a system of elastically bonded slabs on flat surface, simulating the propagation of shear ruptures in super brittle rocks, is analyzed. Such ruptures appear in the Earth’s crust at seismogenic depths. They propagate due to the nucleation of oblique tensile microcracks, leading to the formation of a fan domino-structure in the rupture head. A laboratory physical model was created which demonstrates the process of fan-structure wave propagation. Equations of the dynamics of rotational motion of slabs as a mechanical system with a finite number of degrees of freedom are obtained. Based on the Merson method of solving the Cauchy problem for systems of ordinary differential equations, the computational algorithm taking into account contact interaction of slabs is developed. Within the framework of a simplified mathematical model of dynamic behavior of a fan-shaped system in the approximation of a continuous medium, the approximate estimates of the length of a fan depending on the velocity of its motion are obtained. It is shown that in the absence of friction a fan can move with any velocity that does not exceed the critical value, which depends on the size, the moment of inertia of slabs, the initial angle and the elasticity coefficient of bonds. In the presence of friction a fan stops. On the basis of discrete and continuous models, the main qualitative features of the behavior of a fan-structure moving under the action of applied tangential forces, whose values in a laboratory physical model are regulated by a change in the inclination angle of the rupture plane, are analyzed. Comparison of computations and laboratory measurements and observations shows good correspondence between the results.

Non-Radiometric Dating of the Age of the Earth: Implications From Fossil Coral Evidence

Radioisotope dating has revealed that the age of the Earth is 4.54–4.6 billion years, and these results are widely accepted. However, as with all searches for truth in science, facts should be supported by multiple lines of evidence. Thus, determining the age of the Earth with alternative techniques could serve to strengthen the conclusions that have been reached with radioisotope dating methods. In this paper, a different approach to solving the problem is proposed. As is known from studies of 400 million year old fossil corals, Earth years were 400 days in duration in distant times because the Earth rotated faster than it does today. According to calculations based on the fundamental law of rotational motion dynamics involving the moment of inertia of a body, the radius of the ancient Earth 400 million years ago was 553.379 km less than it is today. This brings us to the impressive conclusion that Earth’s radius grew on average by 1.3834475 mm per year over the past 400 million years. Let us call this the evolutionary Earth growth constant; it does not take into account the effect of lunar tidal friction. If the present day Earth radius of 6371 km is divided by 1.3834475 mm per year, we can estimate the growth time of the Earth from its beginning to the presentthe growth time is 4.6 billion years, which is consistent with the radioisotope data, i.e., 4.6 billion years equals the age of the Earth! This new method for measuring Earth’s age not only confirms outcomes obtained with radiological methods, but it poses new problems and avenues of research for paleogeologists.

Least Squares Method for Attitude Determination Using the Real Data of CBERS-2 Satellite

his work is applied to the dynamics of rotational motion of artificial satellites, that is, itsorientation (attitude) with respect to an inertial reference system. The attitude determination involvesapproaches of nonlinear estimation techniques, which knowledge is essential to the safety and controlof the satellite and payload. Here one focuses on determining the attitude of a real satellite: CBERS-2(China Brazil Earth Resources Satellite). This satellite was launched in 2003 and were controlled andoperated in turns by China (Xi’an Control Center) and Brazil (Satellite Control Center). Its orbit isnear polar sun-synchronous with an altitude of 778km, crossing Equator at 10:30am in descendingdirection, frozen perigee at 90 degrees, and providing global coverage of the world every 26 days.The attitude dynamical model is described by nonlinear equations involving the Euler angles. Theattitude sensors available are two DSS (Digital Sun Sensor), two IRES (Infra-Red Earth Sensor), andone triad of mechanical gyros. The two IRES give direct measurements of roll and pitch angles with acertain level of error. The two DSS are nonlinear functions of roll, pitch, and yaw attitude angles. Thegyros furnish the angular measurements in the body frame reference system. Gyros are very importantsensors, as they provide direct incremental angles or angular velocities. They can sense instantaneousvariations of nominal velocities. An important feature is that it allows the replacement of complexmodels (different torques acting on the space environment) by using their measurements to turn thedynamical equations into simple kinematic equations. However gyros present several sources of errorof which the drift is the most troublesome. Such drifts yield along time an accumulation of errorswhich must be accounted for in the attitude determination process. Herein one proposes to estimatethe attitude and the drift of the gyros using the Least SquaresMethod. Results show that one can reachaccuracies in attitude determination within the prescribed requirements, besides providing estimatesof the gyro drifts which can be further used to enhance the gyro error model.

Students' talk about rotational motion within and across contexts, and implications for future learning

The investigations reported in this article are part of a larger study concerned with understanding learning as it emerges from the enacted curriculum which in itself is mediated by: students' views of the nature of science, beliefs about learning, views of laboratory learning environments; teacher's beliefs about knowing and learning science and knowledge of student ideas about content. In this article, the results of two studies of students' discourse about rotation phenomena are presented with a particular focus on the consistency of this talk across different phenomena. Study 1 presents an inventory of students' observational and theoretical descriptions after they had been taught rotational motion during the previous school year; it simultaneously constitutes an inventory of students' knowing before another physics unit that presupposed knowledge of the first instructional cycle. Study 2 reports on the same students' discourse after a four-week unit on the dynamics of rotational motion. The results of Study 1 indicate that in spite of prior instruction, students' observational and theoretical descriptions of rotational phenomena were different from scientific canon and inconsistent within and across contexts. Study 2 further underscores the variations in student discourse about rotational motion within and across context and the differences with canonical discourse. More importantly, it illustrates that only a minority of students provided adequate observational and theoretical descriptions about the dynamics of rotational motion.

Students' talk about rotational motion within and across contexts, and implications for future learning

The investigations reported in this article are part of a larger study concerned with understanding learning as it emerges from the enacted curriculum which in itself is mediated by: students' views of the nature of science, beliefs about learning, views of laboratory learning environments; teacher's beliefs about knowing and learning science and knowledge of student ideas about content. In this article, the results of two studies of students' discourse about rotation phenomena are presented with a particular focus on the consistency of this talk across different phenomena. Study 1 presents an inventory of students' observational and theoretical descriptions after they had been taught rotational motion during the previous school year; it simultaneously constitutes an inventory of students' knowing before another physics unit that presupposed knowledge of the first instructional cycle. Study 2 reports on the same students' discourse after a four-week unit on the dynamics of rotational motion. The results o...

Light-scattering study of the temperature dependence of Escherichia coli motility

Two light-scattering techniques are used to study the temperature dependence of translational and rotational motility in Escherichia coli. The method of number fluctuation spectroscopy is developed theoretically and experimentally to measure the translational swimming speed of a smooth swimming strain of E. coli. Interference fluctuation techniques are used to study the rotational component of the motion. The results demonstrate that the thrust remains proportional the the torque generated by the flagella throughout the range studied and also show that relative changes in translational swimming speed may be inferred from the dynamics of rotational motion.

Dynamics of rotational motions of a system of solid bodies around the center of mass with variable geometry of the mass

Dynamics of rotational motions of a system of solid bodies around the center of mass with variable geometry of the mass