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The technology of hybrid reinforcements responds to the ever-increasing dynamic demand for services in industries such as automobile, transportation, marine, and aerospace because of its appealing properties like high conductivity, high ductility and light weight. At this level, a study has been conducted to evaluate the microstructure and mechanical characteristics such as tensile strength and hardness of A356 hybrid nanocomposites reinforced with nano Al2O3 (0.5, 1, and 1.5 wt% of Al2O3) and soft solid lubricant nano MoS2 (0.5 wt% of MoS2) using stir casting procedure. Microstructural analysis of A356 reinforced with nano Al2O3 and nano MoS2 hybrid composites was conducted using SEM and which reveals that particles are distributed uniformly in the A356 matrix. The hardness and tensile tests have showed that adding Al2O3 and MoS2 particles to the A356 matrix resulted in a nanocomposite with excellent mechanical characteristics. Theoretical and actual densities of cast composite materials are determined by the Rule of mixture method and Archimedes principle respectively. Actual density of cast composite material is lesser when compared to the theoretical density of the material.

The general physics of how objects float is only partly covered in most undergraduate fluid mechanics courses. Although Archimedes’ principle is a standard topic in fluid statics, the role of surface tension in floating is rarely discussed in detail. For example, very few undergraduate textbooks, if any, mention that the total buoyancy force on a floating object includes the weight of the fluid displaced by the meniscus. This leaves engineering students without an understanding of a wide range of phenomena that occur at a low Bond number (the ratio of buoyancy to interfacial tension forces), such as how heavier-than-water objects can float at a gas-liquid interface. This article makes a case for teaching a more unified version of Archimedes’ principle, which combines the effects of surface tension and hydrostatic pressure in calculating the total buoyancy on floating objects. Sample problems at the undergraduate level and two classroom demonstrations are described that reinforce the basic science concepts.

Este trabalho apresenta uma proposta didática voltada para alunos do Ensino Médio que visa abordar qualitativamente e quantitativamente a força de empuxo. O objetivo desta proposta é utilizar um experimento de baixo custo, feito com materiais simples, para mostrar e explorar a existência e causa do empuxo, além de estruturar um modelo matemático para o cálculo de tal força. Este experimento é útil também para reforçar e demonstrar conceitos sobre hidrostática como pressão e lei de Stevin, que são importantes para o entendimento e análise da força de empuxo. Esta proposta faz parte de um projeto apresentado pelos autores na disciplina Projetos Integrados de Ensino de Física 1, do curso de Licenciatura em Física da Universidade Federal do Paraná. This work presents a didactic proposal aimed at high school students that aims to approach qualitatively and quantitatively the buoyant force. The objective of this proposal is to use a low-cost experiment, made with simple materials, to show and explore the existence and cause of the buoyancy, in addition to structuring a mathematical model for the calculation of such force. This experiment is also useful to reinforce and demonstrate concepts about hydrostatics such as pressure and Stevin’s law, which are important for understanding and analyzing the buoyant force. This proposal is part of a project presented by the authors in the discipline Integrated Projects of Physics Teaching 1, of the licentiate degree course in Physics at the Federal University of Paraná.

We investigate the radiation shielding properties for four Te-based alloys. X-ray diffraction patterns revealed pure phases in all studied samples; however, a secondary phase is detected in the CrTe sample in good agreement with the literature. All samples’ densities were measured using the Archimedes principle. The mass attenuation coefficient (MAC) was calculated using Geant4 MC Toolkit and then compared with the XCOM data. Many photon-shielding properties were computed for all investigated samples based on the MAC. The Phy-X and SRIM were used to determine the fast neutron removal cross-section (ΣR) and projected range, respectively. As a result, PbTe shows superior shielding features compared to the rest of the investigated samples to use this sample in different shielding applications.

Hydrometers are widely used in industry for liquid density measurement. It is important to achieve rapid and high accuracy calibration for hydrometers. Based on the Archimedes principle, a fully automatic hydrometer calibration system in NIM was designed using Cuckow’s method. The liquid density of n-tridecane (C13H28)is calibrated with 441 g high-purity fused silica ring as the solid density standard. The buoyancy of hydrometer is measured by static weighing system with resolution 0.01 mg. The alignment between liquid surface and hydrometer scale was achieved by the lifting platform with the positioning accuracy of 10 μm. According to the weighing value of hydrometer in air and liquid, the density correction value at different scales is calculated. Hydrometer covering a full range (650–1500) kg/m3can be calibrated without changing the liquid. Taking the calibration data of PTB as reference, the experimental data show that the measurement uncertainty of this system is better than 0.3 division (k = 2).

This study aims to determine the effectiveness of practicing problem-solving skills from ESD-based science learning tools. This research is development research with the ADDIE development model and a one-group pre-test post-test design. Data collection methods using validation and tests. Learning tools in all aspects are stated to be very valid so that they can be implemented. The pre-test average score was 52.96 and the post-test score was 79.84 with an N-gain score of 0.67 in the moderate category. This shows that students can be improve in problem-solving skills with ESD-based learning. Students can improved problem-solving skills in the Lapindo mud phenomenon by integrating the liquid pressure material (Archimedes Law and Bernoulli's Law) with the ESD concept (social, ecological, and economic). In terms of ecology, Lapindo mudflow can be overcome by applying Bernoulli's Law. In the economic sector, the overflowing Lapindo mud can be used as a building material. This is studied in the material of Archimedes Law. In the social point, students can communicate the results of problem-solving with the concept of ESD to the surrounding community.

In the present scenario the aluminum and its alloys are preferred due to requirement of lightweight high strength material. The present research article interrogates experimentally the study of actual density and porosity using powder metallurgy method. The experimental design is done using Taguchi L16 orthogonal array. Actual density and porosity has been analyzed based on ‘smaller is best’ basis. Actual density and porosity are calculated using Archimedes principle. The leverage of four levels and five process parameters such as weight percentage of Al2O3, weight percentage of graphite, compaction pressure, compaction time and milling time are considered. Results reveal that Al2O3 weight percentage has the highest leverage on density followed by compaction time and graphite weight percentage.

Aim: To build wounds volume(3D) and area(2D) measuring system and device. Background: The measurement of the wound depth has been troublesome due to difficulty fo the procedures, physicians mostly avoid inspecting the wound depth as it could cause wound inflammation and infection. Objective: To build a contactless device for measuring wound volume and develop the system to support the wound treatment process which offers precise measurement and wound healing progression. Methods: Build a machine to control and stabilize 3D-scanner over the wound using a servo motor and apply the image processing technique to calculate the wound's area and volume. Comparing the machine accuracy by using Archimedes's principle testing with various wound model sizes, made from folding clay and pork rinds. Results: The device and system generate an error value of less than 15% which is within a satisfactory level. Conclusion: Knowing the wound depth is vital for the treatment, direct contact to the wound area can cause inflammation, infection, and increase time to heal. This device will help physicians to get more insight into the wound and improve the treatment plan for the patients. There are certain limitations to be considered for future work. Firstly, different software components used in the image processing and estimation process could be integrated to enhance user experience. Secondly, it is possible to apply Machine Learning techniques to identify the wounded area on the wound image file.

The nature of gravitation and G is not well understood. A new gravitation mechanism is proposed that explains the origin and essence of the gravitational constant, G. Based on general relativity, the vacuum is considered to be a superfluid with measurable density. Rotating bodies drag vacuum and create a vortex with gradient pressure. The drag force of vacuum fluid flow in the arm of the vortex is calculated relative to the static vacuum and a value that is numerically equal to that of G is obtained. Using Archimedes’ principle, it is determined that G is the volume of vacuum displaced by a force equivalent to its weight which is equal to the drag force of the vacuum. It is concluded that the gravitational constant G expresses the force needed to displace a cubic metre of vacuum that weighs one kg in one second. Therefore, G is not a fundamental physical constant but rather is an expression of the resistance encountered by the gravitational force in the vacuum.

Selective Laser Melting (SLM) involves numerous fabrication parameters, the interaction between those parameters determine the final characteristics of the resulting part and because of the latter, it is considered a complex process. Low-density components is one of the main issues of the SLM process, due to the incorrect selection of process parameters. These defects are undesired in high specialized applications (i.e. aerospace, aeronautic and medical industries). Therefore, the characterization of the defects (pores) found in aluminum parts manufacture by SLM and the relationship with fabrication parameters was performed. A robust orthogonal design of experiments was implemented to determine process parameters, and then parts were manufactured in SLM. Relative density of the samples was then characterized using the Archimedes principle and microscopy; the data was then statistically analyzed in order to determine the optimal process parameters. The main purpose of the present research was to establish the best processing parameters of an in-house SLM system, as well as to characterize the pore geometry in order to fully eliminate pores in a future research.

The coexistence of large particles (such as biomass or coal particles) and fine particles in gas-solid flow is common. In this study, an Eulerian-Lagrangian-Lagrangian method (EMMS-DPM-DEM) was developed to simulate the binary gas-solid flow containing particles of significantly different sizes, where fine particles were simulated using coarse grained discrete element method and the motion of large particles was captured using discrete element method. Experiments on density segregation of large particles were also carried out to validate the developed simulation method. It was shown that EMMS-DPM-DEM can predict the density segregation process of large particles reasonably well. Furthermore, the density segregation mechanism of large particles in a dense fluidized bed was explained at different scales, i.e., the Archimedes principle at macroscale, the entrainment and the global circulation pattern due to bubble motions at mesoscale and the particle-particle and gas-particle interactions at microscale. The method proposed here can be directly used to study the hydrodynamics of biomass thermochemical conversion in fluidized beds, although it was validated using segregation experiments of coal particles.

The lesson presented here provides a multifaceted inquiry-based opportunity to develop a deep grasp of Archimedes’ principle. It was originally developed for high school teachers as part of their training in the basic structure of the Next Generation Science Standards. There are numerous demonstrations illustrating Archimedes’ principle, many of which can be found in this journal. (Please see the online appendix for further references from this journal.) However, we have a unique combination of ingredients, i.e., the particular puzzle it addresses and its associated historical context; the biological application; the accessible, hands-on collection and exploration of data; the powerful graphs encouraging physics-based explanations; and the ability to compare with an analytical solution. These materials brought together in one place provide teachers a novel and exceptionally rich recipe to bring to their classrooms.

Background Despite the advances in the techniques of indirect estimation of leaf area, the destructive measurement approaches have still remained as the reference and the most accurate methods. However, even utilizing the modern sensors and applications usually requires the laborious and time-consuming practice of unfolding and analyzing the single leaves, separately. In the present study, a volumetric approach was tested to determine the pile leaf area based on the ratio of leaf volume divided by thickness. For this purpose, the suspension technique was used for volumetry, which is based on the simple practice and calculations of the Archimedes’ principle. Results Wheat volumetric leaf area (VLA), had a high agreement and approximately 1:1 correlation with the conventionally measured optical leaf area (OLA). Exclusion of the midrib volume from calculations, did not affect the estimation error (NRMSE Conclusions It is expected that utilizing the reliable and simple concept of volumetric leaf area, based on which the measurement time might be independent of sample size, facilitate the laborious practice of leaf area measurement; and consequently, improve the precision of field experiments.

Everyone knows that boats, ships, lifejackets, buoys, and even the human body float in the sea. We also know that ice cubes float in our soft drink, that a balloon filled with helium flies upward, as well as one filled with hot air. Moreover, many people are aware that swimming (or at least stay afloat) in the pool is a bit more exhausting than in the sea. All of this is explained by the same physical law: Archimedes’ principle. This law helps anesthesiologists to protect the brain from air embolism, to facilitate de-airing during open-heart surgery, and to handle a syringe.

Students’ conception towards Archimedes principle on the object in a fluid is still miscellaneous. Students’ conception has an important role in their learning process and it also can improve their skills. This research is intended to investigate students’ conception of Archimedes principle on the object in the fluid. The method that has been applied in this research is a descriptive quantitative with three reasoned multiple-choice test instruments based on the static fluid concept. This research was conducted on 101 students in Excellent Al- Yasini High School, Pasuruan and Kepanjen 1 Senior High School, Malang. The quantitative data in this study are based on students’ answers. Comparatively, the qualitative data are obtained by students’ interviews. The results show that there are miscommunications in the previous lesson; therefore, the students’ ability to associate between concepts is subdued. Thus, students’ conception of the buoyant force on an object is that the object is getting closer to the surface of the fluid or getting up, it has a greater lift force.

The performance of the propellant depends on its energy density, which is equal to the density of the propellant multiplied by the energy of the propellant. The actual density of composite propellant can be determined by the Archimedes Principle. And the present theoretical density of composite propellant is calculated by the assumption their component is the same phase and the mixing is homogeneous. But, the apparent density (actual density divided by theoretical density) still more significant low than 100%, which means the actual density more significant difference from the theoretical density. This paper proposed the sphere packing density theory was added to improve the calculation theoretical density of composite propellant. This method produced the result of apparent density a better value close to 100%. The improvement of the theoretical calculation method for composite propellant density can be used as a reference in making a composite propellant formulation design, checking the homogeneity of the composition mixture, and improving the propellant process method.

There is a curious, intuitive fascination about buoyancy at great depths in the ocean. It was reported of ancient mariners that they feared burial at sea because they thought that the weighted body would only sink so far and no further. In some confused way, they thought the depths prevented the body sinking further, so it would drift with the currents. Not a proper burial. We are now clearer about Archimedes Principle, probably the most widely known law of physics.

Underground structures experience transient and sustained hydrostatic uplift forces throughout their service life. Conventionally, Archimedes’ principle is used to conduct uplift design. T...

A buoyant-rectangular cable supported Submerged Floating Tunnel (SFT) can often be used as a waterway crossing even over the vast length and depth following the Archimedes’ principle. The interaction between buoyancy and self-weight controls the static and dynamic behavior of the tunnel. For SFT, weight to buoyancy ratio must be equal or less than one (W/B ≤ 1), so that the tunnel tube can float, where the cable curbs the upward thrust confirming its position, and hence 0.8565 is chosen. Here, SFT is modeled in ANSYS based on the environmental parameters of the Qian Dao Lake (China), where self-weight, hydro-static pressure, vehicular load, and water pressure to the tunnel are considered during nonlinear static analysis. Consequently, it has been observed that the deformations and stresses are in the permissible limit, where maximum equivalent strain exceeds the allowable limit due to its high slenderness, and the maximum strain occurred only at the cable joints.

We study the resistance force of cylindrical objects penetrating quasi-statically into granular media experimentally and numerically. Simulations are validated against experiments. In contrast to previous studies, we find in both experiments and simulations that the force-depth relation consists of three regimes, rather than just two: transient and steady-state. The three regimes are driven by different dynamics: an initial matter compression, a developing stagnant zone, and an increase in steady-state force with a fully developed stagnant zone. By simulations, we explored the effects of a wide range of parameters on the penetration dynamics. We find that the initial packing fraction, the inter-granular sliding friction coefficient, and the grain shape (aspect ratio) have a significant effect on the gradient Kφ of the force-depth relation in the steady-state regime, while the rolling friction coefficient noticeably affects only the initial compression regime. Conversely, Kφ is not sensitive to the following grain properties: size, size distribution, shear modulus, density, and coefficient of restitution. From the stress fields observed in the simulations, we determine the internal friction angles φ, using the Mohr-Coulomb yield criterion, and use these results to test the recently-proposed modified Archimedes' law theory. We find excellent agreement, with the results of all the simulations falling very close to the predicted curve of φ vs. Kφ. We also examine the extreme case of frictionless spheres and find that, although no stagnant zone develops during penetration into such media, the value of their internal friction angle, φ = 9° ± 1°, also falls squarely on the theoretical curve. Finally, we use the modified Archimedes' law theory and an expression for the time-dependent growth of the stagnant zone to propose an explicit constitutive relation that fits excellently the force-depth curve throughout the entire penetration process.

The flow resistance on the pier has always been treated as a focus issue in fluid mechanics with great significance of application. Square, as an important cross-section form of pillar structure, has been applied widely in practice. To investigate the relationship of the formation mechanism of flow resistance on square pier and the trailing vortex zone of the pillar, in this study, the flow resistance of the square pier and the surrounding flow are firstly measured by pressure sensor and particle image velocimetry (PIV). Then, by analogy with the principle of Archimedes, the relationship between the characteristics of flow, the flow resistance and the trailing vortex zone of the square pier is analyzed in detail under different Reynolds numbers (2500≤ Re ≤20000). According to the experiments, the fitting relation between the time averaged relative volume of the tail vortex zone, the time averaged dimensionless flow resistance and the new time averaged dimensionless coefficient of flow resistance formula with varied Re has been found. It shows a good correlation with all of them and each one related well to Re by a quadratic relation. Both Linear and quadratic fitting of the flow resistance with the volume of trailing vortex zone fits relatively well. The linear fitting formula is recommended in practice of relative large flow.

We present a very simple and versatile fiber optic sensor for liquid level measurements based on the Archimedes' law of buoyancy. It includes a proper mass suspended in the liquid with one end fixed to a fiber Bragg grating (FBG) strain sensor, while the remaining fiber termination is fixed to a rigid support. When the liquid level increases inside the tank, the load exerted by the suspended mass on the optical fiber is reduced as a consequence of the increase of the force acting on the immersed mass according to the Archimedes’ law of buoyancy, leading to a reduction of the strain applied to the FBG. The proposed device is able to perform real time and continuous liquid level measurements, and is characterized by sensing features (such as sensitivity and operating range) that exclusively depend on the geometrical characteristics (e.g., shape, diameter, and length) of the suspended mass. Therefore, by a judicious selection of its geometrical features, the proposed device can be customized so as to suit the requirements for the specific application. In addition, the constitutive material of the attached mass can be properly selected in order to confer to the proposed platform the capability to operate in any kind of liquid. Here, as proof of principle, we exploited an aluminium cylindrical mass having a radius of 8 mm and a length of 30 cm, and experimentally demonstrated the capability of the realized device to measure the water level inside a beaker over a range of 25 cm with a sensitivity of ∼27 pm/cm, a resolution of ∼0.04 cm, and a repeatability error of ∼0.1% of the full scale reading. We also demonstrated, both theoretically and experimentally, the possibility to largely tune the sensing performances by acting on the cylinder radius. Obtained results pave the way for the exploitation of the proposed platform for accurate liquid level monitoring in large-scale storage tanks, useful both for petrochemical industry and for agricultural/residential applications.

Physics learning is still considered as learning that is less attractive to some students. Students’ lack of learning interest in physics learning makes their achievement low. The purpose of this study was to develop a learning media of True or False Physics Fun Game Card, so as to make the students interested in learning physics which could increase students' interest and learning achievement. The kind of the card game "True or False Physics Fun Game Card" was developed from a 41 card game which was modified as needed. In True or False Physics Fun Game Card, there were 50 true and false statements. Moreover, there were also points of 10-25 based on the level of difficulty of the statements. The statements made based on the Hydrostatic Law, the Relating Vessel, and the Archimedes Law. The True or False Physics Fun Game Card was developed by using the ADDIE development model which consists of 5 development steps, such as analyzing, designing, development, implementation, and evaluation. This study was tested on 12 samples of the Physics students of Universitas Kristen Satya Wacana. The data obtained were processed qualitatively and quantitatively. Based on the results of this study, it was found that 93.75% of students responded positively toward the learning media “True or False Physics Fun Game Card” and the average value of the students' post-test results was 72.67. The 10 samples from a total of 12 test samples obtained the post-test result; 65, so as the percentage of the successful comprehension sample was 83.33%. This study contributed to increasing kinds of learning media and improving students' learning achievement, especially in physics learning.

Knowledge about the volumetric behavior of epoxy resins (chemical shrinkage) during curing is a basic requirement for constitutive modeling of curing processes in Continuum Mechanics. This paper covers shrinkage measurements while a special hot anhydrid-curing epoxy resin cures. The measuring method is based on Archimedes' principle also for elevated temperatures up to 140 ° C , where a precision scale is drawn on. Moreover, a magnetic suspension between the scale and the sample ensures a constant immersion depth of the sample to avoid negative side effects. Apart from shrinkage measurements, the thermal expansion of the uncured epoxy resin over a comprehensive temperature range is measured using a chemically stable epoxy mixture. Based on an exact description of the deformation, we introduce a model for the thermo-chemical deformations, where it is possible to separate thermal from chemical deformations. This is done under nearly pressure-free conditions to avoid any mechanical deformations regarding the curing kinetics. Using this information, we draw on the most common curing model of Kamal and Sourour to the resulting evolution of the degree of cure, so that DSC measurements can be circumvented. Both methods are compared.

Pores generated in inside of a Nickel-Alumina FGM (functionally graded material) fabricated by pressureless sintering method because of unperfected sintering. These pores change the mechanical properties of the material. To predict accurately variations of the mechanical property, there is a need for accurate measurement of porosity. Conventional method of measuring the porosity measures the outer diameter of the cylindrical specimen and calculated bulk density using it. However, this method did not consider an internal deformation of the specimen, thus the accuracy of its method is lowered. To measure a more accurate bulk density of each layer of the porous FGM than the conventional method, a method using Individual specimen and a method using the Image Processing of MATLAB (IPM) were proposed. To confirm accuracy of the proposed method, the bulk density of the entire FGM calculated by the proposed method was compared with the bulk density of the entire FGM measured by Archimedes' principle. In the comparison results, the result of the method using the IPM was closer to the result of the method using Archimedes principle than the result of the method using the Individual specimen. Thus, this author concludes that the method using IPM is more suitable for measurement of the bulk density of each layer of the FGM than the method using the individual specimens.

The interpretation of the equilibrium of a solid body floating on the surface of a liquid body is well known as the “Archimedes’ Principle”. Presently, the equilibrium of the solid body is interpreted as the result of the concurrence of two mechanical actions which are equivalent and opposite: the “weight” of the body, directed downwards, and the “Archimedes’ force” having a magnitude equivalent to the weight of the volume of liquid displaced by the volume of the body immersed in the liquid, directed upwards. We show arguments proving that this interpretation is not a correct physical interpretation. The same arguments show that a new different interpretation is a correct one. The new interpretation is based on the hypothesis that the “weight” of a body immersed in a body-medium is proportional to the volume of the body immersed in the body-medium and to the difference in density between the matter of the body and the matter of the body-medium. Accordingly, if a body is completely immersed in a body-medium, there is only one mechanical action on the body. This action may be downwards or upwards, or its magnitude may be zero. In this last case, the body is in equilibrium within the body-medium.

In learning physics, Archimedes’ law is a physics material that is quite difficult and requires a deep understanding of concepts based on study files from several schools in Banten. As many as 96.4% of students need online simulation media using computers or androids to help study Archimedes Law material. The Massive Online Simulation (MOS) design is divided into six parts, namely the dashboard, home, materials, videos, simulations and quizzes. This study aims to design a media in the form of Massive Online Simulation (MOS) on Archimedes’ legal material. The method used is ADDIE (Analysis, Design, Development, Implementation and Evaluation). Research and development of the ADDIE model is carried out only up to the Design stage. This research can produce an attractive Massive Online Simulation (MOS) design that can be accessed anytime and anywhere.

Deviations from Archimedes’ principle for spherical molecular hydrogen particles with the radius R0 at the surface of 4He liquid helium have been investigated. The classical Archimedes’ principle holds if R0 is larger than the helium capillary length Lcap ≅ 500 μm. In this case, the elevation of a particle above the liquid is h+ ~ R0. At 30 μm Rc. Here, $${R_c} \cong {\left( {\frac{{\hbar c}}{{\rho g}}} \right)^{1/5}} \approx 1$$ , where ħ is Planck’s constant, c is the speed of light, g is the acceleration due to gravity, and ρ is the mass density of helium. For very small particles (R0 < Rc), the distance h_ to the surface of the liquid is independent of their size, h_ = Rc.

Physics is contain a lot of abstract concept.this thing arise student’s difficulty in learning physics individually. This difficulty can be solved by educators with using the method of cooperative learning on teaching their pupil. Beside of that, on teaching abstract concept can be helped by using virtual media. Because of that, this research is aim to test the effect of cooperative learning with virtual media toward the student’s conceptual understanding in physics on static fluid matter. Pre-test and post-test was gived to experiment and control class. The instrument of the test is conceptual test which consist of six cognitive aspect. The result show that the cooperative learning with virtual media increased student’s conceptual understanding in static fluid and significantly increased at sub-matter Archimedes law and fluid pressure. This result also showed the increase of student’s cognitive abilty on experiment class, but one of cognitive aspect C6 (create), control class more better than experiment class.

The focus of the study is to test the effectiveness of the Conceptual Problem Solving (CPS) learning approach. This study used a mixed-method with embedded experimental design. The quantitative data were obtained from the pretest and posttest results, while the qualitative data were obtained through observation from all activities during the learning process. This study involved 35 XIth students from Science Program. The results showed that the students’ average pretest score is 2,66 (SD = 0,97) and the posttest is 5,54 (SD = 1,33). T-test results obtained a significance value of 0,00. Therefore the difference in the pretest and posttest scores is significant. The d-effect size value is calculated to know how big the influence of learning for students’ understanding. The d-effect size value is 2,51 and is categorized higher than than the standard limit. To describe how strong the improvement of students’ conceptual understanding based on the pretest and posttest scores, the average gain of normalized (N-gain) is calculated. The N-gain obtained 0,39 under the criteria of the lower medium. This research concludes that learning with conceptual problem solving on the 5E learning cycle can improve the XIth student’s understanding of the Archimedes principle.

This study aims to determine the differences of students’ conceptual understanding about Archimedes’ principle in this study conducted with descriptive quantitative method involving 60 students. The instrument consists of open ended questions (r = 0.664). The results of Mann U Whitney test shows that there is significant differences of students’ conceptual understanding between urban and rural area. The mean rank indicates that students in the urban have a higher conceptual understanding in Archimedes principle. Further analytical qualitative shows that high school students from the different areas revealed a difficulty to distinguish hydrostatic pressure and Archimedes’ concepts. Based on these findings, it is hoped that public policies will be more equitable in paying attention to the conditions of students in urban and rural areas.

Life on Earth could not be active without fluids. The behavior of ordinary fluids, whether in use by a life form, or otherwise in nature, follows Newtonian principles. Here we look at the consequences of mechanics applied to fluids, including the oceans, the atmosphere, and our own blood.

A technique based on Archimedes’ Principle is described for measuring the volume of small objects (0.5–5 cm3) less dense than water. The volume of 10 small red chillies was measured by pycnometry and an immersion Archimedes technique which involved suspending the chillies in water in a container placed on an electronic balance. A pycnometer, which uses helium gas is able to determine the internal solid volume of the chillies and water immersion the outer volume. The difference between the two volumes gives the volume of internal air cavities in the chillies. The pycnometer and immersion techniques were compared by measuring the volume of wax candles with volumes between 0.3 and 2.5 cm3. A Bland-Altman analysis revealed that the Archimedes volumes were lower than pycnometry volumes by 6.1 ± 2.3 % which needs further investigation. A combination of pycnometry and water immersion may be a useful tool for botanical studies.

We carried out an experimental study of the floating of a square bar in water and found its equilibrium orientation (tilting angle) as a function of relative density ρ bar/ρ water. Though the theoretical solution of this problem was given in 1963 by Reid, we provided our solution that is more transparent and less cumbersome, enabling an introductory level physics student to follow it. Our experimental method is very simple and easily reproducible in a school-level physics laboratory, and obtained data fit the theoretical results quite reasonably.

Based on Newton’s third law of motion, we present a different but quite general analysis of Archimedes’ principle. This analysis explains the reduction in apparent weight of a submerged object in all cases, regardless of its position in the fluid. We also study the case in which the object rests on the bottom of the container where the net hydrostatic force on it is downward, and explain where in this case the reduction in the apparent weight comes from.

Groundwater buoyancy force, calculated by using the Archimedes' Principle, provides a fundamental basis for the anti-flotation design of buoyant structures. Owning to the limitations of large-scale field measurements and small-scale laboratory model tests, previous practitioners indicated that the measured buoyancy force was slightly different from the calculated Archimedes' buoyancy force. However, this argument is still questionable in the academia. This study hence introduced an experimental investigation of groundwater buoyancy force on shallow foundations embedded in saturated clay ground based on the “half interval” search method. By setting the weight of model buckets in an “arithmetic sequence”, the groundwater buoyancy force was obtained based on the average weight of the “heaviest” model bucket that floated and the “lightest” model bucket that did not float under the same hydrostatic uplift loading. The proposed “half-interval search” method has many advantages, i.e., didn't rely on any instrumentations, avoided limitations of devices/sensors, and maintained high quality of test accuracy. In addition, the complete test processes were recorded, during which the buoyancy force change could be observed lively. Test results demonstrated that the measured buoyancy force on foundations in clay ground was smaller than the theoretical buoyancy force, which is consistent with the large-scale field measurements, indicating that the proposed half interval search method is reliable and robust.

A new dynamic equation of aerosol in air is derived, using a model-in-model, by equilibrium of buoyancy, gravity and pressure, together with conservation laws of mass, momentum and energy via Reynolds transport theorem and supplemented by corresponding scientific laws for related properties of air and aerosols. This new dynamic equation of aerosol in air is a set of non-linear partial differential equations involved six unknown functions of mass densities, pressure, air and aerosol speeds and temperature. It has features: 1, it belongs to certain type; 2, it emphases the effect of buoyancy in equilibrium and potential energy, and the Archimedes principle of buoyancy is firstly extended to lateral directions based on logical deduction, the phenomenon of stirring a glass of oil-water mixture and the recorded of Hurricane Isabel (2003) from space station. The later shows the evidence of existence of lateral buoyancy; 3, the mass densities of air and aerosol of a point in our model are varied in different directions due to traction and are treated as vectors, and they have been used in the calculation of lateral buoyancy.

This paper presents an alternate method of underwater energy storage utilizing an object's inherent buoyancy as a means for storage known as buoyancy battery energy storage (BBES). Utilizing a simple pulley, reel and float mechanism, energy can be stored for an indefinite period of time. Governing equations of charge and discharge are defined through application of Archimedes principle of buoyancy for an ideal system. Inefficiencies, losses as well as potential application configurations are presented and discussed. Basic experimental validation was completed to confirm system properties of constant discharge force with respect to both float position and storage duration.

The conventional porosity measurement is not adequate to precisely measure “as-is” porosity of heavy oil sand samples due to its irregular sample shape, pore-filling viscous fluids, and especially difficult storage without losing mass. From a practical laboratory point of view, a confined porosity measurement strategy is specifically introduced to measure the as-is porosity of heavy oil sand sample. This overall strategy primarily consists of two parts. First of all, as-is porosity is estimated by using the assumed parameters (grain density, fluid density, and fluids saturation) and measured bulk density that is calculated from the Archimedes principle, which not only keeps the sample intact, but also is advantageous for minimizing mass loss and external covers. Furthermore, by extracting the pore fluids (heavy oil, water, and possibly gas) from the original sample, the assumed indispensable parameters are precisely measured; more importantly, a group of porosity data can be calculated by applying directly measured grain volume data and bulk volume data. Based on the measured data and error analysis, we have concluded that the porosity calculated from these directly measured data set gives us a low porosity bound whereas as-is porosity estimated from the Archimedes principle indicates the upper bound.

Applying Newton’s third law, the action and reaction pair of the buoyant force (upthrust) when an object is immersed in a fluid is considered. A discussion follows on how this can be used to solve problems and derive Archimedes’ principle.

A different physical interpretation of floating of bodies - the so-called “Archimedes’ Principle” - relates the gravitational process to its essential characteristic: its spontaneity. Gravity is a spontaneous physical process - similar, for example, to the process we interpret as ‘heat transfer’ between bodies at different temperature; similar to the process which occurs when masses of gas in contact with each other are at different pressures; similar to the process we call ‘friction’. Gravitation has all the characteristics shown by other spontaneous processes, and, like them, its cause is disequilibrium, between matter in contact, in a ‘quality’ of that matter. In the case of gravitation, the quality of matter is related to its intensive property we call ‘density’. Just as the process we call ‘heat transfer’ is the spontaneous process by means of which the Universe reduces and eliminates disequilibria that exist between its parts, due to differences in ‘temperature’, what we call ‘gravitation’ is the spontaneous process by means of which the Universe reduces and eliminates disequilibria between its parts, due to differences in ‘density’. This is achieved by moving bodies. Ceteris paribus, the process moves a body in the direction in which the difference in density between the matter of the body and the matter of the fluid surrounding the body is reduced.

Water strider or Gerridae is very lightweight insect and has a long leg that able to stand and even jump on the surface of water surface tension. Mimicking this creature become one of the favorable areas in the bioinspired robotics field. A Portable Striding pH Tester (PSpHT) is one of the robotics systems that mimicking water strider with quadruped mechanism. The first PSpHT design had successfully operated with real-time pH monitoring, and long-haul remotely control. However, weakness in its footpad still existed when the rapid spatial motions were not making PSpHT faster enough on the water surface. Therefore this paper presents the improvement progress on PSpHT and introducing its second version named PSpHT-II. In this progress, a new footpad with light cylindrical shape is proposed by considering the water surface tension. The polypropylene-based footpad hold with light aluminum alloy as a link of the spatial leg and the flat plate was added as the paddler on each side of the footpad as water surface breaker. The leg design is recalculating and fabricated regarding the Archimedes principle and surface tension theory by considering the balance forces between the air and water. According to the calculations and buoyed test, the proposed cylindrical footpad is less submerged compares to the previous footpads designed. On the other hand, the proposed spatial motion was simulated for verification. As for validation, PSpHT-II was validated by running the system on the lakeside of Universiti Malaysia Pahang, Pekan, Pahang Campus. The experiment shows the additional paddlers help PSpHT-II striding faster and stable although with a mild and windy situation.

The focus of this study is to determine students' difficulties related to mastering the concept of Archimedes Principles topics. The study used descriptive quantitative method with the subject 35 XIth students. The research instrument was 10 multiple choice questions about Archimedes principle. Although there are improvements, but overall students do not fully understand the concept of the Archimedes principle. Difficulties among students are failing to understand that the buoyancy force is the resultant force by fluid pressure on the object and still considers the immersed object to have the Archimedes force affected by the depth of the object. When working on the application of the problem the students managed to answer correctly, but when completing the formulation questions the students were still get difficulties

In learning physics, students often have difficulty in understanding concepts. This certainly has an impact on students’ critical thinking skill. This study aims to analyze students’ critical thinking skills related to the concept of hydrostatic and Archimedes’ principle. This research was conducted using a qualitative descriptive design. The research subjects were students of class XII MIPA in Malang (N = 127). Data collection was carried out through a series of tests in the form of essay and interview questions. The indicator used to create critical thinking questions refers to the five main perspectives presented by Hughes. The results show that the majority of students have relatively low critical thinking skill. It is shown by the average score of critical thinking skill of students which only reached 36.1 from the maximum score of 90. The main cause of the low critical thinking skill of students was the presence of misconceptions experienced by students. The low critical thinking process of students are also caused by students have not yet accustomed to applying the concepts of physics in daily life.

The purpose of this study was to get a description of the students' ability to interpret the static fluid material. This research was a quantitative descriptive study and the sample was taken by purposive sampling technique with a total sample of 26 students at one of the Madrasah Aliyah in the city of Singkawang. To achieve this goal, students had filled in questions about static fluids in a multiple-choice test. The results of this study were a quantitative description of the student's ability to interpret the static fluid material. The interpretive ability category was adapted from the n-gain category. The results showed that the category of students' ability to interpret the concept of hydrostatic pressure and Archimedes principle was in the high category with a percentage of 88% and on the Pascal principle it was categorized as low with a percentage of 19%. The results of this study can be a reference for future researchers to improve aspects of understanding interpreting categories in students.

This study aims to identify the creative thinking skills of vocational school students with Malay ethnicity in solving problems regarding Archimedes law. Creative thinking skill is skill that students must have in the 21st century. Therefore, this skill must be trained through the learning process. This research was conducted on 21 students of class X DPIB with 12 men, 9 women and 15 of them are ethnic Malay, the rest are settled migrants. This research is a case study research. The data obtained were analysed with Rasch Analysis Model (RAM). From the analysis results it was found that the ability of Malay students’ creative thinking was still low. The reliability person is weak and the reliability item is good. The tendency of respondent’s ability to work on problems is smaller than the level of difficulty of the questions. There are differences in the level of creative thinking ability of Malay ethnic and non-Malay ethnic students.

A novel method to primary realize the soon-to-be redefined unit of mass, kilogram, is presented. The new approach will accurately relate the Planck constant to spheres manufactured from natural silicon. Therefore, the precisely known isotopical composition of a 28Si sphere will be transferred to a sphere made of natural silicon with a relative uncertainty of 3 × 10−8. To achieve this objective, the concept of a newly developed hydrostatic comparator, which combines the Archimedes principle with a magnetic suspension coupling, is discussed. This combination allows to improve the major uncertainty contribution of this type of instrument - the temperature stability.

Tilting of foundations during liquefaction of soil is one of the primary concerns for stability of structures constructed in saturated sand in seismically active areas. Niigata earthquake resulted in tilting of a number of buildings. Once tilted, the structure is to be dismantled. Tilting also results in loss of life and property. The main aim of this study is to restrict tilting and allow the structure to float on liquefied soil. During a high-magnitude earthquake, the structure may not float for a long time, but may sink instead of tilting. Archimedes principle has been applied in the present study. The shape of conventional rectangular footing is changed to spherical and trapezoidal section. Shake table tests were performed at different frequencies like 0.5, 1 and 1.5 Hz. Comparisons of tilting and sinking of all the three types of footings were performed. Accelerations imposed on the footings were also measured. Results showed a positive response for a footing with spherical cross sections.

Understanding the response of granular matter to intrusion of solid objects is key to modelling many aspects of behaviour of granular matter, including plastic flow. Here we report a general model for such a quasistatic process. Using a range of experiments, we first show that the relation between the penetration depth and the force resisting it, transiently nonlinear and then linear, is scalable to a universal form. We show that the gradient of the steady-state part, Kϕ, depends only on the medium’s internal friction angle, ϕ, and that it is nonlinear in μ = tan ϕ, in contrast to an existing conjecture. We further show that the intrusion of any convex solid shape satisfies a modified Archimedes’ law and use this to: relate the zero-depth intercept of the linear part to Kϕ and the intruder’s cross-section; explain the curve’s nonlinear part in terms of the stagnant zone’s development., The penetration dynamics of solid objects into granular media has been described by theories that are constrained to the use of phenomenological models or empirical parameters. Here, Kang et al. propose and test a parameter-free model for the dependence of the resistance force on penetration depth.