Defining "force" in everyday terms is not a simple matter. Discusses experience with various examples and shows that it is useful to examine whether students have indeed grasped the correct meaning. (Author/MM)

Finds a strange behavior that contradicts the common notion that the force of kinetic friction is constant and depends only on the normal force. (CCM)

Explains a physics experiment on the dynamics of impact cratering. Measures the spreading velocity of the impact wave and the acoustic signal. (YDS)

In this article we show how to verify that in a fluid surface or film the value of the surface tension (i.e. the free energy per unit area) does not depend on the area of the film itself. The experimental evidence discussed can be obtained extremely simply yet with great accuracy. This experiment is important in that it leads to a deeper…

We consider the situation of a boat pinned or wrapped against a rock by moving water in a river. The force exerted by moving water is calculated and the force required to extricate the boat is estimated. Rafts, canoes and kayaks are each considered. A rope system commonly employed by river runners to extricate a boat is analysed. This system…

A brief description on the work and life of the great physicist scientist Albert Einstein is presented. The photoelectric paper written by him in 1905 led him to the study of fluctuations in the energy density of radiation and from there to the incomplete nature of the equipartition theorem of classical mechanics, which failed to account for…

A study was made of different emotions that prospective primary school teachers report with respect to science subjects, when they were pupils, and during their practice teaching, taking into account the variables gender and the specialty they studied in the secondary education. The study consisted of a questionnaire completed by 63 primary…

In this study, we investigated the relationships among cognitive conflict and situational interest induced by a discrepant event, attention and effort allocated to learning, and conceptual change in learning the concept of density. Subjects were 183 seventh graders from six middle schools in Seoul, Korea. A preconception test, a test of responses…

The purpose of this study was to analyse and compare the physics questions of the university entrance exam (OSS) with those asked at exams at different schools in Turkey in terms of the levels of cognitive domain of Bloom's Taxonomy. The study was carried out in four types of high schools (student age: 14-17): "Ordinary",…

During the past few decades, researchers from a cognitive science tradition and a sociocultural perspective on learning have discussed how to understand students' conceptions of the earth. In this article, some of the questions discussed in this debate are elaborated in relation to meaning making in educational settings. The aim is to illustrate…

A number of factors affect successful implementation of an integrated science curriculum, including various outputs and inputs related to teacher quality such as professional development experiences, adequate planning periods, and adequate content preparation of teachers with regard to content knowledge associated with the curriculum taught. This…

Formulas are derived for the energy, momentum, and angular momentum transmitted by waves of arbitrary shape in an inextensible string by pure transverse waves in a string using Tait's procedure. (Author/CP)

Corrected solutions including radiation damping are obtained from relativistically correct equations of motion for a free electron in a plane electromagnetic wave. (SL)

Describes the treatment of hard-core potentials (nucleon-nucleon interaction) in quantum mechanics. (SL)

Discusses the symbiotic relationship of cosmology and elementary-particle physics. Presents a brief overview of particle physics. Explains how cosmological considerations set limits on the number of types of elementary particles. (RT)