A new system for tracking a metal ball rolling on the slope of the touch panel of a tablet computer was developed. The widespread introduction of tablets in educational environments allows the use of a convenient dynamic measurement in schools.

A simple method is described for measuring liquid density based on stretching of the spring and equilibrium of weight and elastic force. The method involves placing a container with liquid under test on the spring causing a stretch of the spring that is directly proportional to the weight of the liquid. With this technique, the liquid density can…

This paper proposes a simple method to design experiments for drawing the light paths at a lens to find its effective focal length and principal planes. In the designed experiments, long-exposure photography was used to record the light scattered using a moving sheet of paper, thus revealing the light path. According to the proposed experimental…

The magnetic field of Earth, B[subscript e], is an intriguing topic in the introductory physics curriculum that engages students' curiosity and inspires numerous speculations about the nature of this phenomenon. There are several methods for measuring Earth's magnetic field. Probably, the most widespread and visual method of measuring the field in…

Apparatus catalogues of the first half of the 20th century contain a number of clever and simple devices for measuring the index of refraction of a liquid. In some cases students can put together one of these pieces of apparatus and then make their own measurements. The Gilley board was one of the devices that caught my eye, and I would like to…

An easy circuit for measuring the power of a solar panel in physics classroom by using the microcontroller Arduino will be introduced in this article. The measured data is transferred via Bluetooth to the smartphone app 'phyphox' where it is displayed graphically. The circuitry enables measuring the power of a solar panel in different situations…

In this article we present a simple technique for determination of the Young modulus of the material of a metallic ruler using it as a cantilever. This method employs with a slide potentiometer and a digital multimeter. The linear region of potentiometer resistance which is calibrated in terms of length has been used to record the load vs.…

Measuring permeability in a high school physics course has long been a hard task. However, with the advent of using smartphones in the classroom, it is not only possible but even easily done. This paper offers detailed instructions on how to measure permeability using a smartphone's magnetometer, starting with experimentally discovering the…

A simple and economical system that allows one to obtain the characteristic "I-V" curve in solar cells is presented. It is a computer-controlled system suitable as an instrumentation project for students who are learning about photovoltaic systems. This system is based on the use of an "R-3R" ladder circuit as a variable…

Heat transfer is a phenomenon well known from everyday life. It is intuitively connected to the properties of materials, that is, to the physics concept of thermal conductivity relevant for cooking or maintaining the constant temperature in rooms, even without being familiar to the underlying physics. However, measurement of thermal conductivity…

We describe a series of three experiments in which students develop a model system for measuring the LC50 of household substances, using grass seed as the model organism. Students use statistical methods to compare two samples (using chi-square and Student's "t"-tests), conduct a two-level multifactor experiment to look at multiple…

This article reports on a new device, called a geyser guide, that allows for quantitative measurements of both bubble sizes and kinetics of foam production in the so-called Diet Coke and Mentos experiment. The device is easily constructed, is made using readily available materials, and allows the experiment to be carried out indoors with no mess.…

Resonant cavity perturbation as a means to measuring permittivity has been used since the early 1940s. It is attractive because it is non-contact, non-destructive and experimentally simple. Only recently, however, has the cost of a small analyser board become acceptably low that experiments can be carried out in schools and colleges. Using the TE…

This paper describes a very simple, but accurate method of finding the position of the infinity focus of a telescope objective relative to the rear face of its lens cell. The method is easily undertaken in the classroom and provides an opportunity for learners to conduct an interesting and novel optical experiment which introduces thick lens…

The Cosmic-Ray Extremely Distributed Observatory (CREDO) is the project to search and study ultra high-energy cosmic ray particles from deep space producing simultaneous extensive air showers over the entire exposed surface of the Earth. The concept of the CREDO infrastructure assumes absorbing all kinds of cosmic ray data from any apparatus all…