We present a sequence of two physics experiments, designed for use with secondary students, which investigate the specific heat of sand, both qualitatively and quantitatively, without a calorimeter. We use two LM35 temperature sensors and an Arduino prototype board for data acquisition. The results are good and allow teachers to discuss the…

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…

The vertical bounce of a plastic egg was investigated by dropping the egg on a horizontal surface and filming the result with a video camera. If the egg is dropped on one end then it bounces just like a spherical ball. If the top end of the egg is pointing forwards or backwards when it lands on the surface, or if the egg is spinning when it lands,…

The anomalous thermal expansion of water in the 0 °C-4 °C range is extremely important to life on Earth, but it is normally not presented experimentally in educational settings. This paper presents a simple experiment to explore the anomalous thermal expansion of water in the 0 °C-4 °C range and the heat exchange processes in natural bodies of…

In this paper, we present a physical modeling activity whose objective is to allow students to determine the differences between a disk and a sphere using pure scientific criteria. Thereunto, we reproduce the Sun-Earth-Moon system with low-cost materials and compare the illumination effects on the Moon considering two possible shapes for it (a…

In this article, a consecutive series of four hands-on experiments are recommended to teach the colors of paint/pigment and their mixtures. These activities, which are effective in learning about how to make a simple observation and help to build argument-based knowledge about colors, offer an integrated and innovative way of teaching colors of…

Take a selection of balls and marbles along to a nearby playground slide and let students investigate factors that may influence how balls accelerate down an inclined plane. Students can make hypotheses in small groups, plan investigations to test multiple possible explanations and draw conclusions about the importance of different variables. The…

Recently, the physics education community has taken a keen interest in modernising physics education. However, while topics in modern physics have great potential to engage students, these topics are abstract and hard-to-visualise. Therefore, many students hold mistaken pictures and misconceptions, which can impede learning. In this article, we…

In this paper we present a simple dimensional analysis exercise that allows us to derive the equation for the Hawking temperature of a black hole. The exercise is intended for high school students, and it is developed from a chapter of Stephen Hawking's bestseller "A Brief History of Time."

In the transition from classical to modern physics, the idea of taking some certain quantities as distinct or bounded values and keeping the rest continuous has proved useful in dealing with many problems. In this paper we assume an upper bound on the velocity of classical particles and indicate that applying this assumption to electromagnetism…

This paper demonstrates the use of smartphones in an experiment of light absorption and light scattering. The LED display and camera of the smartphone are used as the light source and as the detector, respectively. The color wheel is used to choose the color of the light source to be shone through the sample for analysis. The detector directly…

Newton's cradle is a well-known physics toy that is commonly used by teachers to demonstrate conservation laws in mechanics. It can also be used to investigate the physics of colliding objects, by recording motion of the balls on video film. Various experiments are described using 3-ball and 5-ball cradles, showing how different types of collision…

In this article, physical quantities related to the motion of a parachute system in the framework of Newton's law of mechanics guide an informal approach to the mathematical concept of function. Furthermore, a graphical simulator that enables visualization of the fall of object-parachutes system is presented. The article is aimed at students and…

Given the great interest that black holes arouse among non-specialists, it is important to analyse misconceptions related to them. According to the author, the most common misconceptions are that: (1) black holes are formed from stellar collapse; (2) they are very massive; (3) they are very dense; (4) their gravity absorbs everything; and (5) they…

Over the past 25 years, the Davidson College Physics Department has developed small computer programs called Physlets. These programs were written in Java and distributed as Java applets embedded in HTML pages. Physics teachers from around the world used Physlets to author interactive computer-based curricular materials for the teaching of…