Here, a relatively simple laboratory experiment of a physical pendulum, suitable for students of science and engineering in the first courses of university physics, is presented to illustrate its dynamic behavior and to determine its inertia moment. To this end, a long wooden rod of length L = 99.8 cm and cross-section radius R = 1.73 cm was used…

We have developed new rotors that can be classified into three groups by changing the rotors used in simple motors into various types. Group I has a semicircular shape rather than a perfect circle or square shape, group II has a structure consisting of several closed circles on one plane, and group III has a three-dimensional shape. We wanted to…

The trajectory of a ball rolling across an inclined plane was recorded on video film to determine if it followed a parabolic path as others have suggested. The challenges in this case were (a) to determine the magnitude and direction of the friction force on the ball, (b) to determine the effect of the friction force on the trajectory and (c) to…

When authoring physics problems, professors may develop an intuition for how much information they need to provide such that the problem has a unique answer and is not over constrained. It is an open question as to whether using intuition leads to a sufficiently broad range of problems. In this paper we discuss a systematic way of authoring…

The study of the motion of a projectile, thrown at an angle to the horizon, is a wonderful classical problem. This issue has been the subject of great interest to investigators for centuries. Currently, the study of parabolic motion, in the absence of any drag force, is a common example in introductory physics courses. The theory of parabolic…

In order to fix some important concepts of Fundamental Physics, either because they are not usually discussed in depth in theoretical classes and much less at laboratories, or because they are not sufficiently developed in textbooks, it is more effective not to tackle them directly, but to propose a mental or practical experiment to attract the…

In this work, a simple rocking pendulum, in a circular arc shape, is presented. The idea is to put a rigid arc on a clean flat surface of glass and leave it to oscillate under the effect of a little impulse. Then, the periodic time of this arc pendulum's motion is experimentally determined. The mathematical analysis of the arc's motion is derived…

Experimental results are presented concerning the motion of a ball that bounces up an incline a few times then bounces back down again. The number of bounces up the incline is typically small since the speed of the ball in a direction parallel to the incline decreases rapidly, not only during each bounce but also while the ball is in the air. The…

There are plenty of contributions in the physics literature on the subject of standing waves. What seems to be missing is an accessible, quantitative account of standing waves on a circular path at a level appropriate for undergraduate physics courses. In order to rectify this absence, a straightforward, concise, mathematical description of…

In this article, we demonstrate the use of a simple pendulum to explore the concepts of kinematics and dynamics. A simple homemade pendulum and a phone-based accelerometer are used to determine, at various points in time, the acceleration of a moving train. The dynamical and kinematics data from the homemade pendulum and the accelerator can then…

The oscillations of one mass "m" suspended between two different springs, assuming a friction force proportional to the velocity [minuscule], have been studied. For this purpose, an assembly for this system has been made. The movement of the mass is recorded with a smartphone and analysed with "Tracker." It is obtained that the…

The static equilibrium properties of a spool, resting on an incline and subject to the tension exerted by a string wrapped around the core cylinder, are studied by means of Newtonian mechanics. The overall behaviour of this system is imagined to be similar to that of a doggie kept on a leash. Starting from the well-known mechanical properties of…

Student difficulties with making sense of graphs in physics have been thoroughly reported. In the study of one-dimensional waves, the issue is even trickier since the amplitude is a function of two variables (position and time). In this work, we investigate students' reasoning and difficulties with interpreting the graphical representation of the…

The falling rod paradox, i.e. the fact that the tip of an almost horizontal rod falls with an acceleration 'higher than g', when the other end is hinged or supported, is a popular physics demonstration. It can be visualized by placing e.g. a coin on the tip of the rod and fixing a cup next to the coin. When the rod is released the free-falling…

In this study, we have explored the effectiveness of two instructional approaches in the context of the motion of objects falling at terminal speed in the presence of air resistance. We ground these instructional approaches in dual-process theories of reasoning, which assert that human cognition relies on two thinking processes. Dual-process…