The formulation of the dynamics of a mechanical system can be done by the method of the Port Controlled Hamiltonia System (PCHS), but this method still leaves a Lagrange multiplier. Furthermore, the dynamics can be formulated using another method which is more systematic, namely the Routhian Reduction method. The method illustrates a system that is subject to non-holonomic constraints and external force, so that the Lagrange multiplier can be removed from the equation. Before formulating the dynamics of a non-holonomic mechanical system, the researcher will analyze the potential energy that occurs in a system that moves in the cylinder configuration space. Potential energy is the main part that must be completed to formulate the motion system of an object, because Routhian reduction only reviews the kinetic energy and potential energy in a dynamic system. The dynamical system reviewed is an object that moves both translation and rotation with a non-holonomic constraint, namely the Tippe Top (TT). The author analyzes the potential energy of a mechanical system that moves in a cylinder configuration space with non-holonomic constraints. Method in this research is a mathematical theoretical study. This method can reduce the equation TT’s motion with and without friction that moves on the surface of the cylinder clearly in the form of a set of differential equations. According the result of this riset, the potential energy for the TT with non-holonomic constraints that move on the surface in the tube can be determined by U = mg(r(1 − cos ρ ) + (R − acos θ ) cos ρ + asin θ cos φ sin ρ), transforming the TT’s Lagrangian that moves on a flat plane (Cartesian coordinates) to the tube coordinates, with reference to the height of the plane solved by coordinate transformation.

Tippe top is an example of simple moving system of rigid body with non-holonomic constraint, but the analysis of this system is not simple. A tippe top equation has been derived with Routhian reduction method and Poincaré equation, and physics computation in finding numeric solution of the dynamics of the tippe top has also been utilized by using Maple program. However, the Poincaré equation required that quasi-coordinate of the quasi-velocity is found, while in the case of the dynamics of tippe top, there is not any exact solution of the quasi-coordinate of the quasi-velocity was found. Therefore, the tippe top equation should be reduced to solve the problem. In this research, Routhian reduction was employed so that the Routhian reduction-based Poincaré equation was used to derive the tippe top equation. The method was able to derive a tippe top equation on a flat plane and tube inner surface clearly represented differential equations.

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Physics computing can be used to help to solve complex dynamic equations, both translation and rotation. The purpose of this study was to obtain differences in the dynamics of the tippe top with and without friction moving on inner surface of a cylindrical with varying initial state based of Routhian Reduction. The equation of tippe top in flat fields with and without friction has been reduced by the Routhian reduction method with the Poincare equation with computational in the previous research, and computation has also been carried out in the search for numerical solutions to the dynamics of tippe top with friction in the Maple program. In this study the reduction used is a Routhian reduction, so that the equation used in determining the equations of tippe top motion with and without friction that moves in a curved plane in the form of a cylindrical surface with varying initial state based on maple is Poincaré’s equation based on Routhian reduction with and without friction. The effect of friction can be seen clearly through the dynamics and graph equations in the return top. This method can reduce the equation of backward motion with and without friction that moves on the surface of the cylinder clearly in the form of a set of differential equations. This research can be continued by solving the dynamic equations of the tippe top in other curved fields such as the torus and ball. The findings of this study are dynamic equations and graphs of friction with and without friction equations that move in curved fields in the inner of surfaces in cylinders with varying initial state based on maple.

This study reports the experimental results of the measurement and analysis of the moment of inertia (MOI) of rigid bodies using a smartphone magnetometer. The MOI apparatus comprises a spiral spring, stand, deviation scale, and vibration counter. The magnetometer application used on the smartphone is the Physics Toolbox Sensor Suite. The magnet, which is placed on top of the MOI apparatus, rotates with the rigid body, and the smartphone magnetometer is used to detect the magnetic field values. We experimentally determine the relationship between the magnetic field and time. The time function is used to analyse the oscillation period of the rigid bodies, which comprise a solid cylinder, solid sphere, solid cone, and solid circular disc. The oscillation periods are proportional to the radii of the rigid bodies. This experience will trigger student interest in conducting related experiments.

The thinking ability of Indonesian students is still relatively low, this can be seen from the ranking of Indonesia based on the results of TIMSS in 2015. To improve students ‘thinking abilities and provide reinforcement to students’ abilities, one of the efforts is to equip students with higher-order thinking skills by using questions HOTS is based on the Borg and Gall development model. A Higher Order Thinking Skill (HOTS) instrument has been developed that is subject to a valid and reliable fluid subject in high school using the Borg and Gall development model. This study aims to: 1) produce HOTS physics questions based on a valid and reliable Borg and Gall development model. The trial was carried out in SMAN 3 Palembang with class X MIA 1 students as research subjects. The data collection instruments used consisted of questions grids, question sheets, and validation sheets. The data analysis technique used is item analysis consisting of validity, difficulty level, and different power analysis, and reliability testing. The results of this development are 15 valid questions out of 25 items created. Of the 25 items, 3 items were declared difficult, 20 items had a moderate level of difficulty, and 2 other items were relatively easy. In addition, these questions are also stated to be reliable with a Cornbach’s Alpha value of 0.78. The results of this study indicate (1) data collection as a validation test with an expert lecturer of 4.5 which is very valid. (2) a reliable test in the initial field test stage obtained an average score of the reliability of stages one and two respectively 0.74 and 0.76 with a high level of reliability. Thus, based on the results of the research data it was found that the instrument about HOTS fluid material developed was classified as valid and reliable.

Natural Science subjects consisting of Physics, Chemistry and Biology are given to all students starting from elementary school to equip students with logical, analytical, systematic, critical, and creative thinking skills, as well as the ability to work together. According to the Organization for Economics Cooperation and Development (OECD) in 2013, the conception of Science literacy in the PISA (Program for International Student Assessment) supports the importance of students developing a solid understanding of the concepts of pure science and science education and the benefits involved in exploration in the abstract world that exists. on the universe. This study resulted in an analysis of science learning strategies for students of the Department of Science Education that support higher order thinking skills in Science. Two (2) parts of the material will be discussed more focused, namely (a) learning materials and (b) learning strategies. With the learning syllabus that supports the High Order Thinking Skills (HOTS) questions, the opportunity to increase the value of Science education (Physics, Chemistry, Biology) is greater, one of which is the preparation of challenging questions. Challenging science questions will meet the criteria for high-level questions (PISA has question levels from level 1 to level 6). HOTS questions support the development of a solid understanding of pure Science and Science Education concepts. The data sources used in the preparation of this research are the results of the 2000, 2003, 2006, 2009, 2012, 2015 and 2018. PISA surveys and the 2013 curriculum book sourced from the Ministry of Education and Culture.