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…

For conducting laboratory experiments on Fresnel diffraction, the use of a simple point light source from an LED and the application of a modern smartphone for photographing the diffraction patterns are proposed. The developed devices allow the experiments to be carried out under normal laboratory lighting.

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…

New technologies are being developed every day. Many of these may not make it into the curriculum for technology and engineering students. For those that do, there may be quite a delay between the time the technology is introduced at an industrial scale and when the technology is developed at a relatively low cost and small scale needed to…

This communication describes a method to detect aluminum in gastric drugs by the naked eye using a microfluidic paper-based analytical device ([mu]PAD). Aluminum ions react with chrome azurol S (CAS) and cetyltrimethylammonium bromide (CTAB) to form a colored complex, which generates a colored band on the [mu]PAD. A printed ruler can be used to…

A laboratory experiment characterized by a whole-class data-pooling approach to generate a data set that can be used to test a model of the influence of ionic strength on electrolyte solubility is described and discussed. The design of the experiment makes efficient use of the laboratory period and releases time for instructional and dialogic…

How well does the undergraduate organic chemistry laboratory curriculum prepare students for academic research, or for a bench job in industry? Running experiments that are more representative of research chemistry has the potential to better equip students for working in a research laboratory, while at the same time giving them insight into a…

Interfacial solar vapor generation has recently drawn much attention because of its high solar-to-vapor generation efficiency. Here we introduce the basic experimental procedures and analysis for undergraduates to perform such an experiment to catch up with the cutting-edge research wave. Interfacial solar vapor generation employs an interfacial…

These days, smartphones are popular commodities among students in high school and college. Students carry their devices all the time, so why not use such a popular electronic device to measure physical quantities such as "g" in physics labs? In this work, we report a "multiple tasking" method, a measurement technique that we…

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…

Participants gave recognition judgments for short lists of pictures of everyday objects. Pictures in a given list were an equal mixture of three types that varied according to the way they were used as targets and foils earlier in the same session. Under consistent-mapping (CM), targets and foils never switch roles; under varied-mapping (VM),…

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…

This study is the result of a quantitative analysis of the previous paper reporting on four cases in which an LED is turned on by charge transfer occurring during the electrostatic induction process in a conductor connected to the LED. We were able to measure the charge transfer by using charge sensors and analyze experimental results by applying…

With the advancements in broad-spectrum sunscreens and the recent bans on benzene-based sunscreens due to their environmental toxicity, there has been a push toward broad-spectrum sunscreens containing in organic active ingredients. In this study, a procedure was developed to analyze the particle size and size distribution of inorganic active…