An original approach using three appropriate Pythagorean triangles is presented for the detailed mathematical analysis of an ideal conical pendulum. The triangles that are used in this analysis relate specifically to the physical dimensions of the conical pendulum, the magnitudes of the forces acting during the conical pendulum motion and a…

We created an introductory physics activity for undergraduate students, consisting of measuring the same physical quantity by different methods. This allows us to confront students with questions of uncertainty, precision, and model versus theory. The aim was to measure the height of a building using only a smartphone and everyday low-cost…

In 1936, Albert Einstein wrote a brief article where he suggested the possibility that a massive object acted as a lens, amplifying the brightness of a star. As time went by, this phenomenon--known as gravitational lensing--has become a powerful research tool in astrophysics. The simplest and symmetrical expression of a gravitational lens is known…

In a typical high school course, the complex physics of collisions is broken up into the dichotomy of perfectly elastic versus completely inelastic collisions. Real-life collisions, however, generally fall between these two extremes. An accurate treatment is still possible, as demonstrated in an investigation of coin collisions. Simple…

Two curious thought experiments concerning the speed of light are presented which have been used to provoke the interest of undergraduate physics students. (Contains 2 figures.)

A 2 m long wooden beam provides an ideal demonstration tool for exploring moments. A class set is cheap and can be used at introductory and advanced levels. This article explores how such beams can be used to support learning about moments, equilibrium, vectors, and simultaneous equations. (Contains 7 figures.)

This paper presents a derivation of all five Lagrange points by methods accessible to sixth-form students, and provides a further opportunity to match Newtonian gravity with centripetal force. The predictive powers of good scientific theories are also discussed with regard to the philosophy of science. Methods for calculating the positions of the…

Presents a method to solve differential equations of free damped oscillators, so that general (periodic and aperiodic) solutions can be obtained, solely on the basis of elementary knowledge of differential and integral calculus and avoiding the use of complex functions. (GA)