In this paper, the dynamic case of a system made up of two blocks connected by a string over a smooth pulley is revisited. One mass lies on a horizontal surface without friction, and the other mass has a vertical displacement. The motion equation is obtained and its solution is determined using the "Mathematica" package. Also an…

When injecting dye into a vortex, one finds that the dye remains captured around the vortex core over minutes, despite the fact that the vortex (and the dyed region) is strongly time-dependent. According to a recent theory, three-dimensional time-dependent vortices should be defined as rotating, material-holding regions of the fluid. Vortices…

Measuring the "e/m" ratio is a classic experiment in the physics curriculum. We show that smartphones can reliably measure the magnetic field strengths involved. Moreover, phone cameras and the image-processing software Tracker can make determining the charge-to-mass ratio of the electron more accurate.

The fact that a bungee jumper can reach an acceleration greater than the acceleration of gravity is, also from a physics point of view, intriguing. Taking only gravity into account, it can be explained by applying conservation of energy or by deriving carefully the equation of motion in a Newtonian approach. In this article we show how it can be…

Carbohydrates are an essential group of molecules to the organic chemistry classroom providing molecular relevance to a common ingredient in chemical biology. While the meticulous elucidation of the carbohydrate structures by Fischer and others is an engaging topic in the lecture, there are few laboratory experiments that can emulate carbohydrate…

A continuous flow photopinacol coupling of benzophenone has been developed and implemented in the undergraduate laboratory. This photoreduction was accomplished using 2-propanol as an H atom donor and cosolvent in the reaction. The simple and inexpensive UV light source and flow reactor design (less than $350/photochemical flow system) provide an…

Williamson ether experiments are commonly performed by students in undergraduate organic chemistry instructional laboratory courses. In this multioutcome experiment, students were provided 4-bromophenol and one of three alkyl halides: 1-bromopentane, 1-bromobutane, or 1-bromo-3-methylbutane. The alkyl halides served as the unknown component of the…

An undergraduate organic chemistry experiment has been developed that features asymmetric synthesis of an enantioenriched secondary alcohol, followed by determination of its absolute configuration using the competing enantioselective conversion (CEC) method. Students are given a ketone and an unknown enantiomer of CBS (Corey-Bakshi-Shibata)…

Physics experiments powered by a universal serial bus (USB) connection are becoming increasingly common. With teachers going through so many batteries each year, USB-powered physics provides an economical and environmentally friendly alternative. In this article, the authors discuss several ways that USB power can provide a convenient way to do…

We show that the gravitational acceleration g near Earth's surface can be easily determined with high accuracy by conducting the usual free fall experiment in high school or college physics laboratories. Unlike the conventional method of data analysis that uses formulas without taking air resistance into account, we consider the effect of air drag…

Enzymes are widely applied in different industries, like pharmaceutical, food, biofuel, and waste valorization. However, the enzyme operating conditions are very limited. So, in most industrial processes, enzymes are not efficient, due to the use of harsh conditions, like organic solvents, extreme pH, and temperature. Immobilization arises as a…

The purpose of this mixed-methods research was to investigate changes in preservice elementary teachers' science teaching beliefs and explain how these beliefs influence the way these teachers interpret their science teaching and learning experiences. Supported by the theoretical underpinnings of teacher beliefs and drawings as a tool to…

In this study, it is aimed to calibrate an LDR-Lux meter with a calibration setup which includes a light bulb whose brightness can be changed by using a dimmer circuit, a data acquisition card, a smartphone and a lux meter application. In order to make the measurements more accurate and to prevent errors in the measurements, a smartphone and a…

We developed new teaching materials, electrical resistors and capacitors, using carbon nanotube (CNT) paper and carbon fibre (CF) paper to foster students' creative thinking, thereby deepening and extending learning. Using a CNT-paper electrical resistor, it is possible to elucidate the dependence of the resistance value on the length and width.…

In science learning, the experiment is an essential activity to facilitate students to discover and develop knowledge as well as to enhance scientific process skills and self-confidence. This study aims to create a simple experimental apparatus related to the principle of fluid continuity that can be made and conducted by the teacher and student…