Calculations are presented showing that the usual 'faster than g' demonstration has a surprising property. That is, a rod hinged at its bottom end rotates at an exponentially increasing rate until it falls with maximum vertical acceleration, unlike an object that falls freely by gravity alone. If the rod is hinged at its top end and released from…

In this article we show that the electrostatic field intensity of a uniformly charged straight line equals that of the corresponding arc of a circle charged with the same linear density. This new method greatly simplifies the calculation of the electrostatic field of a system consisting of uniformly charged straight lines.

In the article 'How Long Is My Toilet Roll--A Simple Exercise in Mathematical Modelling' several models of increasing complexity are introduced and solved to calculate indirectly the length of paper on a toilet-roll. All these results are presented without errors. The authors of this comment believe the error analysis of measurements made in a…

Science and engineering students in the second semester of a calculus-based physics sequence typically study and measure the on-axis magnetic field for a multiple, circular turn coil. There are four benefits to this approach: 1) an analytical solution is easily obtained, 2) the coil is easily constructed using tightly wound, high-gauge wire where…

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…

We discuss the limits of the equation of the period of a simple pendulum, T[subscript s] = 2[pi][square root]l/g, frequently used in high-school and university classrooms to measure the acceleration of gravity. We evaluate the relative error in determining the acceleration of gravity with this simple equation instead of a more realistic one,…

Mathematics education often grapples with the challenge of teaching abstract mathematical concepts, particularly those existing in 3D space. Visualizing, manipulating, and comprehending these abstract objects can be a formidable task for learners. While 3D printing technology has found applications in various fields, its utilization in mathematics…

According to NCTM's "Principles and Standards for School Mathematics" (2000), the act of estimating is reflective of students' mathematical intuition and number sense. Students with more developed number sense are better able to judge the reasonableness of their results. To promote estimation, Jennifer Marshall explored incorporating…

In a paper (posthumously) co-authored by Isaac Newton himself, the primacy of geometric notions in pedagogical expositions of centripetal acceleration has been clearly asserted. In the present paper we demonstrate how this pedagogical prerogative can inform the design of an experiment involving an accelerometer-equipped smartphone rotating…

This article focuses specifically on the inclusion of meaningful (but potentially messy) real-world mathematics tasks in the middle school classroom. Real-world tasks provide students with learning opportunities allowing mathematics to be used to understand the world, strengthen mathematical knowledge, and offer opportunities for students to use…

"Where Mathematics Comes From" (Lakoff & Núñez 2000) proposed that mathematical concepts such as arithmetic and counting are constructed cognitively from embodied metaphors of actions on physical objects, and four actions, or 'grounding metaphors' in particular: collecting, stepping, constructing and measuring. This article argues…

Although geometry is important and strongly related to our surroundings, students still have few chances to learn it through practicing in authentic contexts. Therefore, ubiquitous geometric (UG) APP in mobile devices was developed in this study and allowed students to apply and practice geometry in authentic contexts. This study focused on the…

Integrating the disciplines of mathematics and science is one way to place the calculations of volume and surface area into a real life context. The authors present an activity for middle-school students that aims to promote their learning of these key concepts in a personally meaningful way, whilst also developing inquiry and problem solving…

The problem of determining the angle ? at which a point mass launched from ground level with a given speed v[subscript 0] will reach a maximum distance is a standard exercise in mechanics. There are many possible ways of solving this problem, leading to the well-known answer of ? = p/4, producing a maximum range of D[subscript max] = v[superscript…

It is well known that the length and orientation of a shadow cast by a vertical gnomon depends on the time of the day and on the season of the year. But it also depends on the latitude of the site of observation. During the equinoxes, the temporal sequence of the shadows cast by each of the points that form any object follows a straight line from…