Newton's laws are a ubiquitous topic in introductory physics instruction. One common problem involves asking what will happen if you stick your finger into a cup of water sitting on a scale. A way to solve the problem would be to first recognize that the water exerts a buoyant force upward on the finger, which students can recognize as being the…

A safe, convenient, and environmentally benign laboratory experiment for the synthesis of biodiesel from six kinds of vegetable oils has been developed for the introductory organic chemistry laboratory. The experiment uses ultrasonic irradiation in the presence of a base catalyst at room temperature and atmospheric pressure. Because of safer and…

Using everyday life examples is proven didactically useful for teaching physics, as it presents effective applications of physical laws. Cooking and food, in particular, serve two useful purposes: on one side, they are able to engage students in the study of physics with familiar examples; on the other side, thanks to the wide range of physical…

Laboratory work in physics has traditionally focused on the verification of facts, theories and laws. In contrast, this article describes how laboratory tasks can be used to promote students understanding about the nature of science and scientific inquiry. In the project reported here, students learn about measurement uncertainties and a…

Thin-layer chromatography (TLC) is one of the basic analytical procedures in chemistry and allows the demonstration of various chemical principles in an educational setting. An often-overlooked aspect of TLC is the capability to quantify isolated target compounds in an unknown sample. Here, we present a suitable route to implement quantitative…

The act of swinging an object such as a hammer or a tennis racket involves the application of forces and torques in a manner that is intuitively obvious to the person performing the task, but is probably much less obvious to the average physics student. This article describes the basic mechanics of the problem.

The two independent methods of measurement of the mass of ice created at sudden solidification of supercooled water are described. One is based on the calorimetric measurement of heat that is necessary for melting the ice and the second interprets the volume change that accompanies the water freezing. Experimental results are compared with the…

A simple inductive gravimeter constructed from a rigid plastic pipe and insulated copper wire is described. When a magnet is dropped through the vertically mounted pipe it induces small alternating voltages. These small signals are fed to the microphone input of a typical computer and sampled at a typical rate of 44.1 kHz using a custom computer…

There is a popular myth that Galileo dropped two objects of the same shape but different mass, noted their equal fall time, and concluded that gravitational motion is independent of the mass of the object. This paper demonstrates that this experiment--if actually performed--most likely would have yielded a different result and thus with modern…

In this paper we present three different methods for testing Bernoulli's law that are different from the standard "tube with varying cross-section." They are all applicable to high-school level physics education, with varying levels of theoretical and experimental complexity, depending on students' skills, and may even be…

Measurements are presented on the rise of a spinning egg. It was found that the spin, the angular momentum and the kinetic energy all decrease as the egg rises, unlike the case of a ballerina who can increase her spin and kinetic energy by reducing her moment of inertia. The observed effects can be explained, in part, in terms of rolling friction…

Everyone enjoys seeing the cloudy white fog generated when solid carbon dioxide (dry ice) is placed in water. Have you ever wondered what physical and chemical processes occur to produce this fog? When asked this question, many chemical educators suggest that the fog is produced when atmospheric water vapor condenses on cold carbon dioxide gas…

Teaching prismatic colours usually boils down to establishing the take-home message that white light consists of "differently refrangible" coloured rays. This approach explains the classical spectrum of seven colours but has its limitations, e.g. in discussing spectra from setups with higher resolution or in understanding the well…

New media technology becomes more and more important for our daily life as well as for teaching physics. Within the scope of our N.E.T. research project we develop experiments using New Media Experimental Tools (N.E.T.) in physics education and study their influence on students learning abilities. We want to present the possibilities e.g. of…

Two new semiquantitative green chemistry metrics, the green circle and the green matrix, have been developed for quick assessment of the greenness of a chemical reaction or process, even without performing the experiment from a protocol if enough detail is provided in it. The evaluation is based on the 12 principles of green chemistry. The…