The flight trajectory of a water rocket can be reasonably calculated if the magnitude of the drag coefficient is known. The experimental determination of this coefficient with enough precision is usually quite difficult, but in this paper we propose a simple free-fall experiment for undergraduate students to reasonably estimate the drag…

Gaia theory proposes that a cybernetic system including the biota and the physicochemical environment regulates environmental variables at a global scale, keeping them within a range that makes Earth inhabitable by living beings. One can argue that this theory can play an important role in school science, since it bears upon current environmental…

The Sun's atmosphere is a highly structured but dynamic place, dominated by the solar magnetic field. Hot charged gas (plasma) is trapped on lines of magnetic force that can snap like an elastic band, propelling giant clouds of material out into space. A range of ground-based and space-based solar telescopes observe these eruptions, particularly…

We discuss three methods of measuring the density of air most commonly used in a teaching context. Emphasis is put on the advantages and/or difficulties of each method. In particular, we show that the 'rubber balloon' method can still be performed with meaningful physical insight, but it requires a very careful approach. (Contains 4 figures and 3…

A series of experiments involving the synthesis and characterization of a benzene-1,3,5-tricarboxamide derivative and its self-assembly properties are reported. These laboratory experiments combine organic synthesis, self-assembly, and physical characterization and are designed for upper-level undergraduate students to introduce the topic of…

Liquid chromatography (LC) experiments for the undergraduate analytical laboratory course often illustrate the application of reversed-phase LC to solve a separation problem, but rarely compare LC retention mechanisms. In addition, a high-performance liquid chromatography instrument may be beyond what some small colleges can purchase. Solid-phase…

Students determine the relative atomic masses of calcium, magnesium, and aluminum by reaction with hydrochloric acid and measurement of the volume of hydrogen gas liberated. The experiment demonstrates stoichiometry and illustrates clearly that mass of the reagent is not the determinant of the amounts in chemical reactions. The experiment is…

Developing scientifically literate students who understand the socially contextualized nature of science and technology is a national focus of science education reform. Science educators' perceptions of risks and benefits of new technologies (such as biotechnology) may shape their instructional approaches. This study examined the perceived risk of…

Science curriculum and instruction in K-12 settings in the United States is currently dominated by an emphasis on the science standards movement of the 1990s and the resulting standards-based high-stakes assessment and accountability movement of the 2000s. We argue that this focus has moved the field away from important philosophical…

Still largely based on EuroCanadian knowledge and Western teachings, Education in Nunavut remains a negative experience for many Nunavut youth as the result of culturally inappropriate schooling and worldview mismatch. Mismatch occurs as the schooling experiences of Nunavut youth, both Inuit and non-Inuit, do not align with the character, values,…

When a moving ball collides elastically with an identical, initially stationary ball, the incident ball will either come to rest (head-on collision; see Fig. 1) or will acquire a velocity that is perpendicular to that acquired by the target ball (oblique collision; see Fig. 2). These two possible outcomes are related in an interesting way, which…

This paper tries to demonstrate that it is not reasonable to judge the quality of pictures that a camera can produce just by the number of pixels that the sensor has. It does so by trying to relate the number of pixels in a picture to the resolution that the eye can see at various distances away from prints of different size.

This paper describes an enjoyable, simple, and inexpensive way to perform Young's two-source experiment using sound waves. The wave source is a simple aluminum rod (a "singing rod").

The similar mathematical forms of Coulomb's law and Newton's law of gravitation suggest that two uniformly charged spheres should be able to orbit each other just as two uniform spheres of mass are known to do. In this paper we describe an experiment that we performed to demonstrate such an orbit. This is the first published account of a…

Diapocynin (5,5'-dehydrodiacetovanillone) was synthesized by oxidative coupling of apocynin (acetovanillone, or 4-hydroxy-3-methoxyacetophenone). Diapocynin is a metabolite of apocynin, which has anti-inflammatory and anti-oxidative properties. The oxidizing agent was an in situ generated sulfate radical, produced by adding iron(II) sulfate and…