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…

Existing research identifying common student ideas about forces focuses on students' misunderstandings, misconceptions, and difficulties. In this paper, we characterize student thinking in terms of resources, framing student thinking as continuous with formal physics. Based on our analysis of 2048 written responses to conceptual questions, we…

The classic brachistrochrone problem is standard material in intermediate mechanics. Many variations exist including some accessible to introductory students. While a quantitative solution isn't feasible in introductory classes, qualitative discussions can be very beneficial since kinematics, Newton's laws, energy conservation, and motion along…

While the three laws of conservation of energy, momentum, and angular momentum are all mentioned in introductory textbooks, there are few experiments through which students can investigate the conservation of angular momentum. Most experiments consist of collisions between rotating disks, in which one disk is dropped on another, or in which the…

We propose an experimental analogy to verify Kepler's second law using a spherical pendulum. We made a movie of a closed elliptical orbit of the pendulum and extracted the data position using the Tracker software. Analyzing the data, we measured the areas that the position vector sweeps showing the validity of Kepler's second law.

Newton's cradle is often discussed in science classrooms as a clear example of the laws of conservation of momentum and energy although it has been shown that this use is somewhat misleading. Approaches to understanding the behaviour of this apparatus are often over-simplified and deficient or over-complex and with little impact among teachers. In…

Regular disciplinary instruction of introductory physics at high school often misses a holistic perspective of the subject matter, its structure, and hierarchy. We have considered the domain of classical mechanics as taught at school and provided such a perspective in the form of a summative lecture which frames content in the triadic structure…

When a ball bounces obliquely on a horizontal surface, the bottom of the ball stretches horizontally and then vibrates backward. The resulting ball spin depends sensitively on the transverse vibration frequency. A simple model is presented to describe the effect, showing how the stored elastic energy can result in additional spin.

We report on an investigation of student thinking about steady-state pipe flow of an incompressible fluid. About 250 undergraduate engineering students were given a test consisting of two hydrodynamics questions, combining multiple-choice format with subsequent open-ended explanations. There is substantial evidence that students have difficulty…

In the transition from classical to modern physics, the idea of taking some certain quantities as distinct or bounded values and keeping the rest continuous has proved useful in dealing with many problems. In this paper we assume an upper bound on the velocity of classical particles and indicate that applying this assumption to electromagnetism…

Students' understanding of forces in circular motion is often incomplete. The problems are not limited to confusions about centripetal acceleration and centrifugal forces. This paper considers possible effects of different interventions by a teacher who has discovered the many types of free-body diagrams drawn by students for circular motion in a…

Large drop towers let you experience a couple of seconds of nearly free fall before stopping gracefully in magnetic brakes or bouncing a number of times on compressed air, as in the Turbo Drop tower considered in this work, where many complementary representations are used. An accelerometer taken along on the ride captured the forces experienced…

Newton's cradle is a well-known physics toy that is commonly used by teachers to demonstrate conservation laws in mechanics. It can also be used to investigate the physics of colliding objects, by recording motion of the balls on video film. Various experiments are described using 3-ball and 5-ball cradles, showing how different types of collision…

The vertical bounce of a plastic egg was investigated by dropping the egg on a horizontal surface and filming the result with a video camera. If the egg is dropped on one end then it bounces just like a spherical ball. If the top end of the egg is pointing forwards or backwards when it lands on the surface, or if the egg is spinning when it lands,…

In the companion paper, "Aerodynamic Lift, Part 1: The Science," I described the key features of lifting flows. The objective of the present paper is to explain those features and the cause-and-effect relationships between them in a manner consistent with the laws of physics. [For Part 1, see EJ1195081.]