The purpose of this publication is to present a novel approach to the demonstration of the Dzhanibekov effect. The main idea of our version is to use a lightweight spinning top of a spherical external form but distinct principal moments of inertia floating in the upward flow of air. As a result, the Dzhanibekov effect can be easily demonstrated…

In traditional introductory physics courses, concepts of distance, displacement, speed, velocity, scalars, and vectors are generally taught near the beginning of the course. However, students often contend with preexisting notions, such as the idea that speed and velocity are synonyms, which present some of the first conceptual hurdles that they…

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…

SHAPE America has outlined proactive ways to approach movement opportunities during physical education class. These possibilities can range from structuring the student learning experience to how teachers implement instruction. While movement provides a foundation for many of the activities offered, what is not discussed is how to use stillness,…

To a student in introductory physics, using vectors is at best an exercise in bookkeeping. A two-dimensional kinematics problem effectively doubles the number of equations that a student must know, and invites the student to memorize factoids: "The horizontal motion is constant," "Gravity is only in the y-direction," etc. Force…

When deriving the equation describing the transverse motion of a one-dimensional vibrating elastic string, introductory physics textbooks often assume constant tension and/or small amplitude vibrations. However, these simplifying assumptions are not only unnecessary, but they overlook the elastic nature of the tension and yield an inconsistent…

In high school, and also in introductory physics courses in higher levels of schooling, the law of universal gravitation of planets is introduced by postulating Johannes Kepler's three laws, and later Isaac Newton's law of the inverse of the square of the distance to the Sun. The justification of the laws is only achieved in advanced courses in…

One of the contemporary trends in the development of physics teaching is its integration with computers. Introducing computers and microcontrollers into the teaching of physics opens up completely new possibilities for explaining different physical phenomena. Microcontrollers allow the experiment to be brought back to the focus of physics teaching…

It can be a challenge to come up with simple demonstrations of circular motion and conservation of energy. One such demonstration consists of a large exercise ball, off of which a small solid ball is rolled. The small ball is coated in finger paint so, after an initial push, it rolls nearly without slipping and creates a visible track.

Newton's laws are essential for understanding causes and description of mechanical motion. Great attention is paid to them during physics education. Unfortunately, many students, not only in high school, but also undergraduates, can recite them but do not understand their essence. Therefore, it is useful to demonstrate different experiments in the…

Ever increasing technological progress opens novel opportunities concerning educational activities, and the ability to use the technology effectively is one of the 21st century's most demanding skills. The Partnership Forum for 21st-Century Skills (P21) states that no organization can achieve satisfying results without using technology and…

Ciphers based on rotor machines were the state-of-the-art in the mid-1900s, with arguably the most famous being the German Enigma. We have found that students have great interest in the Enigma and its cryptanalysis, so we created our own rotor cipher that is simulated with shifting tables and can be cryptanalyzed. Ours and the historic rotor…

When we travel in a train moving at a certain velocity, we observe the stationary objects outside are moving backwards. These stationary objects seem to move due to a relative velocity. Consider that the stationary object outside the train is a man standing on the stationary floor watching a woman moving on a train. The woman on a train will see…

A solid ball placed on a rotating turntable is known to roll slowly around a circular path, at a speed 3.5 times slower than the turnable itself. If the ball is located in a straight track across a diameter of the turntable, then it accelerates rapidly to the edge. Both effects were filmed in slow motion using a video camera and a cake decoration…

Fernández-Chapou and colleagues analyzed projectile trajectories and showed an elliptic property hidden in them. For that analysis, they considered projectiles shot from a point with a common value of speed and different angles of projection. Such projectile paths exhibit some interesting characteristics. For example, pairs of projectiles with…