Technically simple and extremely cheap setups for colorimetric and fluorimetric analyses using a smartphone camera are presented. Laboratory activities on digital colorimetric and fluorimetric analyses for students of secondary and higher educational institutions are proposed, namely, photocolorimetric determination of acetylsalicylic acid in…

The study of buoyancy becomes very interesting when we measure the apparent weight of the body and the liquid vessel weight. In this paper, we propose an experimental apparatus that measures both the forces mentioned before as a function of the depth that a cylinder is sunk into the water. It is done using two load cells connected to an Arduino.…

Charging a capacitor with a photovoltaic module is an experiment which reveals a lot about the modules characteristics. It is customary to represent these characteristics with an equivalent circuit whose elements represent its physical parameters. The behavior of a photovoltaic module is very similar to that of a single cell but the electric…

When sound waves are taught at the secondary level, the speed of propagation of sound is one of the most important characteristics to be analyzed. However, it is very common in textbooks that the value of sound speed in air is considered constant regardless of the experimental conditions. The great question is that since sound is a mechanical…

Measuring voltage-current and voltage-power curves of a photovoltaic module is a nice experiment for high school and undergraduate students. In labs where real sunlight is not available this experiment requires a solar simulator. A prototype of a simulator using LED lamps has been manufactured and tested, and a comparison with classical halogen…

The Ruben Flame Tube is named after H. Ruben, who published the demonstration experiment in "Annalen der Physik" in 1905. This article presents one of the many demonstrations the author uses to engage, motivate, and challenge his students.

All technology educators have favorite lessons and projects that they most desire to teach. Many teachers might ask why teach robotics when there are many other concepts to cover with the students? The answer to this question is to engage students in science, technology, engineering, and math (commonly referred to as STEM) concepts. In order for…

The construction of an amperometric biosensor for glucose analysis is described demonstrating that the analysis is easy to perform and the biosensor gives good analytical performance. This experiment helped the students to acquire problem-solving and teamwork skills, allowing them to reach a high level of independent and critical thought.

Presents a simple experiment to compare the performance of the PASCO Introductory Dynamics System with that of an Ealing student air track. Discusses the relative advantages of both. Concludes that for a wide assortment of motion activities in a low friction environment, or studies of frictional forces, the PASCO Introductory Dynamics System is a…

A relatively simple opto-electronic setup is described that utilizes a cadmium sulphide (CdS) photoconductive cell to detect resonance of a stretched vibrating string or wire. The display may be either an oscilloscope or a frequency counter. Also describes an inexpensive socket for flanged-base light bulbs. (JN)

Describes the working of the Adiabatic Gas Law Apparatus, a useful tool for measuring the pressure, temperature, and volume of a variety of gases undergoing compressions and expansions. Describes the adaptation of this apparatus to perform isothermal measurements and discusses the theory behind the adiabatic and isothermal processes. (JRH)

Describes a simple apparatus used to demonstrate the thermal conductivity of gases. Procedures for completing the demonstration are included. (JN)

Describes the design and use of a projectile motion apparatus to illustrate a variety of projective motion results typically discussed in an introductory course. They include independence of horizontal (constant speed) and vertical (constant acceleration) motions, parabolic path shape, and other types of motion. (JN)

Describes the experimental and theoretical details for constructing and calibrating an inexpensive, homemade liquid-lens refractometer. Measures refractive indices that are within the experimental errors discussed and close to the literature values. (JRH)

Students in hydrogeology classes commonly have difficulty appreciating differences between the mechanisms of water release from confined and unconfined aquifers. Describes a simple and inexpensive laboratory model for demonstrating the hydraulic responses of confined and unconfined aquifers to pumping. Includes a worked example to demonstrate the…