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We recorded diffraction patterns using a commercially available slit and sensor over a wide range of experimental circumstances, including near- and far-field regimes and oblique incidence at large angles. We then compared the measured patterns with theoretical intensity curves calculated via the numerical integration of formulas derived within the framework of scalar diffraction theory. Experiment and theory show particularly good agreement when the first Rayleigh–Sommerfeld (R-S) formula is used. The Kirchhoff formula, though problematic in the context of mathematical consistency, agrees with the first R-S formula, even for large incidence angles, whereas the second R-S formula differs visibly. To obtain such a good agreement, we replaced the assumption of an incident plane wave with that of a Gaussian beam and implemented geometric corrections to account for slit imperfections. These results reveal how the scope of scalar diffraction theory can be extended with a small set of auxiliary assumptions.

Earlier research has shown that students have tremendous difficulties with understanding certain aspects of rolling without slipping, such as the zero-velocity at the contact point and plausibility of application of the law of conservation of mechanical energy despite action of the friction force. The aim of this research was to explore whether using analogies and reasoning about extreme cases can facilitate conceptualization of the above-mentioned phenomena. A pre-test – post-test quasi-experiment has been conducted, with 93 students in the control group (CG) and 91 students in the experimental group (EG). Whereas control group students received conventional teaching, in the experimental group rolling of a cylinder has been considered as a special case of a tumbling prism for which the number of prism surfaces tended to infinity. The results of analysis of covariance showed that students from the experimental group significantly outperformed their peers from the control group on the Rolling Motion Concept Test (RMCT). Between-group differences were greater on test items that required higher level of cognitive transfer. This research suggests that using analogies and extreme case reasoning can facilitate comprehension of certain seemingly counterintuitive aspects of rolling motion. Keywords: analogy-based teaching, energy conservation, extreme case reasoning, misconceptions, rolling motion.

This work is aimed at exploring some pedagogical opportunities of using photographs in physics instruction. In our study, the photography has been used for eliciting and probing students’ ideas regarding the physics of fluids in noninertial frames of reference and under conditions of equilibrium. The study involved a heterogeneous sample of 235 secondary school students, 41 physics students, and 48 physics teachers. They were presented with a photograph of a wine glass filled with liquid whose surface appeared inclined. The students were asked to comment on the reality of the phenomenon captured in the photograph, and the teachers were asked to predict the students’ responses. The results showed that about half of the students had a complete or partially complete understanding of the physical ideas and that their practical and conceptual knowledge was not dependent on their education level or curriculum followed. Most of the respondents found the task interesting and relevant. The results indicate that the teachers’ expectations regarding students’ understanding of physics often significantly depart from reality. We suggest that physics teachers include some photography-based problems and discussions in their classes. This could encourage a broad participation of students with different levels of abilities.

In this work we describe the development of the kinetic molecular theory of liquids (KMTL) concept inventory, as well as its use in investigating students' conceptual understanding of the KMTL within the contexts of aggregate states, evaporation, boiling, condensation, conduction, convection, diffusion, and surface tension. We implemented think-alouds to prepare distractors for the closed-ended version of the KMTL, which was administered to two groups of respondents: non- physicists and physicists (166 students in total from the Universities of Rijeka and Split, Croatia). From the think-alouds and results of written survey research we drew conclusions about the students' understanding of the structure of matter, thermal internal energy, entropy, temperature, and pressure. Our study not only reiterates earlier findings on students' ideas about the KMTL, it also reveals numerous additional misconceptions that had not been reported earlier. Psychometric analyses support a formative use of the KMTL inventory. The inventory questions may be extensively used for identifying misconceptions, as well as for stimulating classroom discussions and conceptual change.

In this research we asked the fourth year students (N = 50) of a technical faculty of the University of Split (Republic of Croatia) to solve a partially specified physics problem related to gravitational force. The task for the students was to decide whether the situation described in the problem is feasible or not. Nevertheless, the formulation of the problem is such that it does not give students any explicit advice regarding what to calculate or how to judge the feasibility of the given situation in the real world. The research was carried out using a structured written exam method. The worksheet was structured in order to assess explicitly a few elements of the students' problem-solving performance. Based on their results, the examinees were classified into four categories, depending on what they could or could not accomplish during problem solving. A majority of students were not able to solve the given physical problem completely. A selection of students' and professors' observations is also included. Our results show that traditionally formulated numerical exercises, which are mostly used in physics teaching, do not develop students' abilities in higher-order thinking (i.e. planning, decision making or result evaluation) to a desirable extent. We suggest that partially specified problems should be given to students, both in problem-solving sessions and exams, in order to prepare them for dealing with ill-structured tasks in real life.

Many physics curricula are opened with the study of kinematics, because such practice is considered to be a logically grounded way for introducing the students with fundamental concepts and methods of pyhsics. Consequently, the approach to teaching kinematics significantly influences not only the students' knowledge of kinematics, but also their learning of other areas of physics, as well as their attitudes towards physics instruction, in general. It is theoretically supposed that understanding of kinematics can be fostered by providing the students with external visualizations, as well as with the opportunity to take measurements of physical quantities. In our study, we aimed to compare the impact of simulations, sequences of simulation frames and conventional static diagrams on students' learning performance in one-dimensional kinematics. Our student sample consisted of three classes of middle years students (N=63 ; mostly 15 year olds). Each of these classes has been assigned to one of the experimental treatments, whereby the treatment variable reflected the use of the abovementioned media types. In order to answer our research question, we conducted a pre- post quasi- experiment with three comparison groups. The results of the ANCOVA showed that students who learned from simulations or from printed sequences of simulation frames significantly outperformed their peers who learned one-dimensional kinematics from conventional static diagrams. Thereby, the results of our study indicate that learning from sequences of simulation frames seems to be particularly productive for girls. Finally, the data from our attitude survey suggest that students are very motivated for learning from simulations or sequences of simulation frames and they consider them as a very useful tool that considerably helped them to learn the difficult kinematical concepts.

We calculate the magnetic fields of cylindrical coils due to a surface current and a volume current and compare our theoretical results to measured magnetic fields of two coil types: single-layer solenoid and cylindrical thick coil by a simple experimental apparatus. Good agreement is found with the theoretical results.

In this work we analyze the wave–particle aspects of radiation in (incoherent) Compton scattering in the radiation energy range from 2–100 keV. From the calculated cross sections of the scattering from the electron (positron), hydrogen and positronium we construct the interpretation functions (IFs), where our assertion is that the Compton scattering from the free electron (positron) is an established example of the particle behavior of radiation. These IFs estimate the possibility of the interpretation of radiation in terms of waves or particles in an analogy with the analysis carried out in the coherent scattering of light. Based on these IFs we propose a new criterion for the estimation of the validity of the impulse approximation (IA).

Students' reflections on the meaningfulness of physics problem statements and solutions were investigated. The sample consisted of 276 Croatian high school/university students. The students, being at the different learning levels, were all familiar with the physical concepts concerned. Students’ critical thinking processes were explored based on their responses to two open- ended ill-defined problems. Further, the teachers' ability to predict the typical students' approach to problem solving was investigated. For this purpose, 48 teachers were administered the closed- ended questionnaire composed of the empirically obtained students' responses to the two ill- defined problems. The results show that ill- defined problems have the potential of eliciting a whole diversity of deep-rooted students’ ideas regarding the meaningfulness of problem statements and solutions. Further, the results indicate that the level of students' critical thinking is low regardless of their educational level and curriculum. It seems that traditional teaching does not sufficiently develop critical thinking. The teachers correctly judge the students’ ability to consider the meaningfulness of the solution but they significantly overestimate their criticism towards the problem statement. We believe this kind of problems could facilitate the teachers’ efforts directed at systematically developing the students’ critical thinking processes. Consequently, students’ coping with ill-defined problems could help them to improve their real- life competences, as well as to develop the habit of taking a critical attitude towards the statements and solutions of physics problems.