Collisions are a key topic in physics and engineering education. An experiment with multiple body one-dimensional collisions is presented, aiming to measure relevant physical quantities by tracking the motion of the system of particles during the collision. Relations between different physical quantities can be explored in the experiment, such as…

Pinhole camera photography is explored using a set of entomology pins due to their known pin diameters and availability in a variety of sizes. A procedure to prepare removable-lens digital cameras for pinhole photography is described. A video is included showing a set of ten insect pins and how to fit the camera with pinhole apertures. Formulas…

Your body is not a point particle. The nature and direction of the forces counteracting gravity influence your experience of uniform rectilinear motion--as does your own orientation in relation to the force of gravity. Sensors in smartphones or other devices can capture these forces, and help establish a connection between the personal experience…

This research aims to develop a falling chain experiment apparatus using kitchen scales and digital cameras (smartphones). Digital cameras were used to observe and record changes in the mass of falling chains measured using kitchen scales. Video recordings from observations of falling chain masses were analysed using Tracker 5.1.1 software. The…

Students are amazed when I show them a zoo photo of an animal behind a fence and then a zoomed-in photo where the fence has disappeared. They ask 'Where did the fence go?' This paper will explore this magical phenomenon which draws from concepts in photography (angle of view, depth of field) and physics (convex lenses, focal length, real images).…

In this article we present simple and low-cost experiments about the polarization of light. We use an LCD monitor or an RGB LED light bulb with a Polaroid as a source of polarized radiation, a polarizer sheet as an analyzer, and a smartphone camera to measure light intensities. Thus, using a digital camera to acquire videos students can explore in…

The objective of this study is to design a temperature measurement system based on a non-contact method using a sensor camera from a webcam. The material being measured is nickel wire given an electrical current of 4.5 A-6.5 A with an interval of 0.5 A. The temperature measurement is based upon the measurement of the average pixel value…

This paper is inspired from a scene in the movie "Memento" (2000), where the eyeglass prescription for a myopic eye can be estimated since the virtual image of a distant wall seen through the lens and a nearby actor outside the view of the lens are located at the same distance. The estimate illustrates that there are times when the power…

There are many physics experiments with long time scales such that they are usually neither shown in the physics class room nor in student labs. However, they can be easily recorded with time-lapse cameras and the respective time-lapse videos allow qualitative and/or quantitative analysis of the underlying physics. Here, we present some examples…

Image modelling is a recent technique in physics education that includes digital tools for image treatment and analysis, such as digital stroboscopic photography (DSP) and video analysis software. It is commonly used to analyse the motion of objects. In this work we show how to determine the position of the centre of mass (CM) of objects with…

Video analysis with a 30 Hz frame rate is the standard tool in physics education. The development of affordable high-speed-cameras has extended the capabilities of the tool for much smaller time scales to the 1 ms range, using frame rates of typically up to 1000 frames s[superscript -1], allowing us to study transient physics phenomena happening…

A very old and well-known magical trick is the so-called tablecloth pull. A table is covered with a tablecloth, on top of which are certain objects. The task is to remove the tablecloth while the objects--which must not be touched--stay on top of the table. This article describes the physics behind the experiment, and presents examples recorded…

In this paper I propose a method of calculating the time between line captures in a standard complementary metal-oxide-semiconductor (CMOS) webcam using the rolling shutter effect when filming a guitar. The exercise links the concepts of wavelength and frequency, while outlining the basic operation of a CMOS camera through vertical line capture.

Surprisingly colourful views are possible from sparkling white snow. It is well known that similarly colourful features can exist in the sky whenever appropriate ice crystals are around. However, the transition of light reflection and refraction from ice crystals in the air to reflection and refraction from those in snow on the ground is not…

A simple but accurate method for measuring the Earth's radius using a video camera is described. A video camera was used to capture a shadow rising up the wall of a tall building at sunset. A free program called ImageJ was used to measure the time it took the shadow to rise a known distance up the building. The time, distance and length of…