The statics of fluids may seem simple at first but often poses problems for students when it comes to applying it to concrete cases. Despite its relatively simple laws, some subtleties, mainly related to the elastic characteristics of a fluid, must be noted. This elasticity allows the pressure exerted in a part of the fluid to propagate in its…

Microfluidics has attracted widespread interest in the fields of chemicals, materials, pharmaceuticals, biology, etc. Integrating low-cost automation based on open-source hardware/software to improve lab security and reduce time consumption is demanded in microchemical processing. In this work, we developed a "do it yourself"…

Teaching special relativity to lower-division students is challenging because results such as time dilation, length contraction, and frame dependence of simultaneity are counterintuitive. The literature is extensive, so only a brief list is given here, with articles divided roughly between discussions of general principles and calculations applied…

In recent years, there have been a number of articles published concerning whether or not potential energy ("PE") as defined in mechanics is invariant under Galilean transformation. This essay addresses that issue in a different, more fundamental and elegant way than has been done thus far. It recognizes that a considerable change in the…

It is well known that Newton's work on mechanics depended in a crucial way on the previous observations of Galileo. The key insight of Galileo was that one can analyze the motion of bodies using experiments and mathematical equations. One experimental observation that roughly emerges from this work in modern terms is that two objects of different…

Bridges are a popular topic in this journal, because they are a very visual display of static and dynamic physical principles. In this paper, we provide an intuitive derivation of the equations associated with suspension bridge cables and load-bearing arches, which is of pedagogical interest in illustrating the consequences of Newton's laws for…

The tidal forces generated by a black hole can be so powerful that they cause unlimited stretching, known as spaghettification. A detailed analysis of this phenomenon requires the use of Einstein's theory of general relativity. The aim of this paper is to offer an up-to-date and accessible analysis of spaghettification, in which the complex…

Background: Research on cognitive effects of educational games in general shows promising results. However, there are large variations in learning outcomes between individual educational games. Research on the design process and different design elements of educational games has led to some interesting directions, but some design aspects remain…

In high school, and also in introductory physics courses in higher levels of schooling, the law of universal gravitation of planets is introduced by postulating Johannes Kepler's three laws, and later Isaac Newton's law of the inverse of the square of the distance to the Sun. The justification of the laws is only achieved in advanced courses in…

The classic brachistrochrone problem is standard material in intermediate mechanics. Many variations exist including some accessible to introductory students. While a quantitative solution isn't feasible in introductory classes, qualitative discussions can be very beneficial since kinematics, Newton's laws, energy conservation, and motion along…

Student understanding of the laws that describe the flow of a fluid is often hampered by a defective knowledge of basic classical mechanics (kinematics, statics, dynamics, and conservation laws) and by wrong common-sense ideas about quantities related to fluids, such as velocity and pressure. A pedagogical discussion about the Venturi effect,…

Self-explanation, a learning strategy where students explain to themselves the steps taken in a worked example, is an effective learning strategy in early cognitive skill acquisition. However, many physics students produce self-explanations of low quality. There is also a lack of guidelines for what students should seek to explain when studying…

Newton's cradle is often discussed in science classrooms as a clear example of the laws of conservation of momentum and energy although it has been shown that this use is somewhat misleading. Approaches to understanding the behaviour of this apparatus are often over-simplified and deficient or over-complex and with little impact among teachers. In…

Regular disciplinary instruction of introductory physics at high school often misses a holistic perspective of the subject matter, its structure, and hierarchy. We have considered the domain of classical mechanics as taught at school and provided such a perspective in the form of a summative lecture which frames content in the triadic structure…

Newton's cradle is a well-known physics toy that is commonly used by teachers to demonstrate conservation laws in mechanics. It can also be used to investigate the physics of colliding objects, by recording motion of the balls on video film. Various experiments are described using 3-ball and 5-ball cradles, showing how different types of collision…