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…

The conical pendulum is a classic introductory physics problem for teaching circular motion--a topic about which students frequently carry alternative conceptions. As teachers provide lessons to untangle these conceptions, it is good to allow students to practice their new knowledge in varied settings. This is one possible experiment that builds…

In order to fix some important concepts of Fundamental Physics, either because they are not usually discussed in depth in theoretical classes and much less at laboratories, or because they are not sufficiently developed in textbooks, it is more effective not to tackle them directly, but to propose a mental or practical experiment to attract the…

Every so often an article appears in the popular press pointing to the apparent confusion surrounding the topic of aerodynamic lift and alleging that even the "experts" don't fully understand it. This makes attention-grabbing copy, but it overstates the case. Actually, the science of lift is not in dispute. It is well understood in terms…

This lesson focuses specifically on teaching concepts of speed and its impact on energy, as well as providing a basic introduction to potential and kinetic energy to fourth-grade students. "Next Generation Science Standards" ("NGSS") 4-PS3-1 states that students should be able "to use evidence to construct an explanation…

Teaching cosmology at the undergraduate or high school level requires simplifications and analogies, and inevitably brings the teacher into contact with at least one of the pedagogical interpretations of the expanding Universe. The by far most popular interpretation holds that galaxies in an expanding Universe are stationary, while space itself…

Along-standing energy lab involves dropping bouncy balls and measuring their rebound heights on successive bounces. The lab demonstrates a situation in which the mechanical energy of a system is not conserved. Although students enjoyed the lab, the author wanted to deepen their thinking about energy, including the connections to motion, with a new…

On entry to university, high-achieving physics students from all across Australia struggle to identify Newton's third law force pairs. In particular, less than one in ten can correctly identify the Newton's third law reaction pair to the weight of (gravitational force acting on) an object. Most students incorrectly identify the normal force on the…

Using a conventional notation for representing forces on diagrams, students were presented with questions on the interaction between two objects. The results show that complete understanding of Newton's Third Law of Motion is quite rare, and that some problems relate to misunderstanding which force acts on each body. The use of the terms…

Anyone who has taught introductory physics should know that roughly a third of the students initially believe that any object at rest will remain at rest, whereas any moving body not propelled by applied forces will promptly come to rest. Likewise, about half of those uninitiated students believe that any object moving at a constant speed must be…

Some misconceptions about physics are hard to change. For example, students continue to believe that heavier objects fall faster than light ones, even after a year of physics instruction. Physics misconceptions are persistent. Light objects do fall more slowly if their size-to-weight ratio is sufficient for drag to be appreciable. Motion through a…

One way to probe students' misconceptions about science during instruction is by using formative assessments. Described as assessments "for" learning rather than assessments "of" learning (Black and Wiliam 1998), they provide teachers with information about student understanding during instruction. Examples of formative…

We consider the application of both conservation of momentum and Newton's laws to the Moon in an assumed circular orbit about the Earth. The inadequacy of some texts in applying Newton's laws is considered.

We propose the use of smartphone-based slow-motion video analysis techniques as a valuable tool for investigating physics concepts ruling mechanical wave propagation. The simple experimental activities presented here, suitable for both high school and undergraduate students, allows one to measure, in a simple yet rigorous way, the speed of pulses…

Newton's second law is one of the cornerstones of the introductory physics curriculum, but it can still trouble a large number of students well after its introduction, hobbling their ability to apply the concept to problem solving and to related concepts, such as momentum, circular motion, and orbits. While there are several possibilities for…