Oblique angle collisions of two penny coins on a smooth, horizontal surface were filmed with a video camera to investigate the physics of the collision process. If one of the coins is initially at rest, then the two coins emerge approximately at right angles, as commonly observed in billiard ball collisions and in puck collisions on an air table.…

Measurements and calculations are presented showing how the trajectory of an object sliding across an inclined plane varies with the launch and incline angles. The trajectory depends on the magnitude and direction of the sliding friction force. The experiment is easy to set up, can be analysed using a video camera, and would be suitable for a…

Points near the top end of a falling rod hinged at its bottom end can fall faster than g. If a rod falls on a frictionless surface then the bottom end slides backwards and the centre of mass falls vertically with acceleration less than g. The effect was simulated by mounting a rod on wheels and filming the result with a video camera. The…

This mixed-methods study examines how pre-service teachers select instructional videos on YouTube for physics teaching. The study focuses on the role of surface features that YouTube provides (e.g., likes, views, thumbnails) and the comments underneath the videos in the decision-making process using videos on quantum physics topics as an example.…

[This paper is part of the Focused Collection on Qualitative Methods in PER: A Critical Examination.] Qualitative research methods have provided key insights in physics education research (PER) by drawing on non-numerical data such as text or video data. While different methods towards qualitative research exist, they share two essential steps:…

Drop Tower Physics (DTP) is composed of a set of experiments using standard physics lecture demonstration equipment, such as a pendulum, mass spring oscillator, and so forth, while videotaping them as they fall freely in the Dryden Drop Tower in Portland, OR. An article published in "The Physics Teacher" illustrated the behavior of a…

Video instruction has been widely studied and is generally considered as effective as live instruction for teaching scientific concepts and procedures. However, there is limited research on the effectiveness of prerecorded videos for teaching more challenging content. This study conducted a controlled experiment on over 300 high school students to…

We have developed a stereo vision system for observing real objects for experimental physics demonstration. The stereo vision observes objects from two different points of view. An observer can identify the distance and velocity of an object based on at least two different points of view. This paper demonstrates our comprehensive observation in a…

Since the vibration of a single pendulum is very periodic, measuring its period is a very interesting topic. When students are asked to measure the period of a single vibration, they start and stop the stopwatch when the pendulum reaches the top point as a reference point. In this paper, we try to show that the error can be reduced more by using…

Water rockets can be used in a variety of ways, from schools to planetariums, with very young kids or adults. We propose here simple forms to work with water rockets, going one step further than a simple launch. A smartphone can be used to film the launch and analyze its motion with video analysis or it can even be attached to the rocket, using…

The toppling motion of falling chimney stacks has been the subject of a number of studies which address the interesting phenomenon that brick chimneys usually break well before they hit the ground. Modern concrete chimneys, and wind generator towers, however, are strong enough to topple without breaking and many videos of their destruction are…

Some of the online explainer videos for physics present misconceptions as scientifically correct explanations. Even so, some of these videos achieve good ratings on online platforms. A possible reason is that explainer videos with misconceptions foster an "illusion of understanding"--the mistaken belief that a topic has been understood.…

Qualitative studies in the domain of physics education research have become more common in the last several decades. Methodologically, this has been marked by an expansion of the types of data collected in physics education research (PER): namely, in the use of individual and group interviews, problem-solving sessions, and classroom…

In socially shared regulation of learning, adaptation is a key process for overcoming collaborative learning challenges. Monitoring the learning process allows learners to recognize the situations that require a need to change, revise, or optimize the current learning process. This can be done through adapting their strategies, task perception,…

The image of free-falling bar has been recorded to study the effect of the motion on its observed length. This moving bar image is analysed using the Tracker software to determine its length and the end bar's position. An elongated appearance of the bar has been observed with movement. This effect relies on the speed and the exposure time during…