In this paper, we present a novel dynamical approach to teach circular motion. According to the principle of inertia, objects without external influences move in a uniform and straight way. With a kick, one can turn the motion towards one side. By successively continuing these turns, a complete circle can be reached. With the help of standard…

Some new experiments using an improved version of the "tornado tube" are described here. The improved tornado tube consists of two plastic transparent bottles whose openings are connected with a ball valve, available at most hardware stores. After being filled with fluid and inverting, this tube allows demonstration of the generation,…

Physics instructors recognize the value of kinesthetic experience in learning fundamental physics concepts. We describe a kinesthetic experiment appropriate for both college and high school physics students. The experiment helps students achieve an intuitive understanding of Newton's second law in a way they find quite enjoyable. It was devised by…

This work reports a rudimentary approach to teach and measure the kinetic friction coefficient using a smartphone that can effectively be employed for teaching purposes. More specifically, the kinetic friction coefficient, which is rather difficult to teach and measure, between various surfaces was determined by two different approaches using the…

In sports, it is very common to see athletes performing jumps, where they impose rotations to their own bodies' elements and intentionally change their moment of inertia around the centre of mass (CM). When this occurs, weird effects are observed in the body's trajectories. In this work we study a jump called "Grand Jeté" of a ballerina,…

For more than 10 years, I had taught Kepler's laws and the law of universal gravity without a corresponding experiment. I sometimes remember how these topics were difficult for me in my high school days to understand. At that time, I thought that one of the reasons for my difficulty was that these phenomena cannot be visualized using physical…

Undergraduate lab design balances several factors: 1) simple experiments connected with learning objectives, 2) experiments sufficiently accurate for comparisons between theory and measurements without gaps when students ascribe discrepancies to confounding factors (imperfect simplifying assumptions, measurement uncertainties, and "human…

The concepts of the Coriolis and the centrifugal force are essential in various scientific fields and they are standard components of introductory physics lectures. In this paper, we explore how students understand and apply concepts of rotating frames of reference in the context of an example lecture demonstration experiment. We found in a…

Research on the impact of guided investigation, including verbal guidance strategies, has expanded in the recent decade, and the current work contributes to this line of research in a museum context. The current in-depth study examines the impact of verbal guidance strategies on family learning at an open-ended museum exhibit, considering…

This paper describes the use of a smartphone's sensors to investigate the motion of a torsion pendulum to demonstrate energy conservation. The smartphone was placed on and attached to a metal disk hanging by a wire. The oscillation of the disk was measured using the smartphone's sensors to simultaneously record angular position, angular speed and…

A novel method of measuring the coefficients of kinetic and rolling friction is proposed. The method is simple to implement and reliable. Samples of measurements and calculations are presented.

When a hard object rolls on a soft surface, or vice versa, rolling friction arises from deformation of the soft object or the soft surface. The friction force can be described in terms of an offset in the normal reaction force or in terms of energy loss arising from the deformation. The origin of the friction force itself is not entirely clear. It…

MEMs gyros, such as those in smartphones allow the angular velocity of pendulums to be precisely measured at large angles, and phase plots of the angular acceleration versus the angular displacement confirm that [double dot][phi] = -[omega][superscript 2][subscript o] sin[phi] even for the non-sinusoidal motion at amplitude [phi][subscript o]…

The relative speed concept was chosen since it is linked with the relative nature of motion and it is likely that the students would harbor many alternative conceptions about it. The research objective was to identify the various ways students conceive relative motion. Qualitative data collected in various forms of representation received a…

A cylinder rolling down an inclined board is a commonly seen and interesting object to study and it is also easy to experiment with and model. Following what has become a popular practice, we use smartphones to measure the angular acceleration of a cylinder rolling down a plane of different inclining angles. The friction force deviates from the…