Perhaps the most commonly cited student idea about forces in the literature is the notion of an impetus force, defined as the "belief that there is a force inside a moving object that keeps it going and causes it to have some speed," that can then "fade away as the object moves along." According to the literature, even after…

To a student in introductory physics, using vectors is at best an exercise in bookkeeping. A two-dimensional kinematics problem effectively doubles the number of equations that a student must know, and invites the student to memorize factoids: "The horizontal motion is constant," "Gravity is only in the y-direction," etc. Force…

When deriving the equation describing the transverse motion of a one-dimensional vibrating elastic string, introductory physics textbooks often assume constant tension and/or small amplitude vibrations. However, these simplifying assumptions are not only unnecessary, but they overlook the elastic nature of the tension and yield an inconsistent…

Electromagnetism (E&M) is often challenging for students enrolled in introductory college-level physics courses. Compared to mechanics, the mathematics of E&M is more sophisticated and the representations are more abstract. Furthermore, students may lack productive intuitions they had with force and motion. In this article, we explore the…

This study proposes methods of reporting results of physics conceptual evaluations that more fully characterize the range of outcomes experienced by students with differing levels of prior preparation, allowing for more meaningful comparison of the outcomes of educational interventions within and across institutions. Factors leading to variation…

Problems involving rotating systems analysed from an inertial frame, without invoking fictitious forces, is something that freshman students find difficult to understand in an introductory mechanics course. In this article we try to see what could be the factors that lead to this difficulty and propose a set of arguments that could be used to…

The sensation of weightlessness is common to an astronaut in a spaceship orbiting Earth and to a person aboard a freely falling elevator. This paper presents a detailed treatment of this commonality by showing that a spaceship orbiting Earth is in permanent free fall toward the planet, appropriate for use in the introductory classroom.

Most springs do not simply obey Hooke's law because they are constructed to have an initial tension, which must be overcome before normal elongation occurs. This property, well known to engineers, is universally neglected in elementary physics courses. In particular, the standard simple harmonic motion experiment omits any discussion of this…

Today's students are increasingly immersed in a landscape of screens and handheld digital devices through which a good deal of their interactions with the world around them are mediated. Physics educators, meanwhile, continue to rely on traditional human interactions with the physical world, such as sliding down a ramp or throwing a baseball, in…

At the introductory level, projectile motion is usually considered under the assumption of the absence of air resistance. Even the simplest case of linear drag might be beyond the students, as it requires some familiarity with differential equations. This leaves many students wondering about the effect of air resistance on the motion and the way…

Researchers have shown students develop misconceptions in projectile motion for various reasons. A common misunderstanding among first-year high school physics students is the notion that the horizontal and vertical components are interchangeable in projectile motion. The students' incorrect reasoning is connected to their personal experiences…

In introductory physics laboratories, spring constants are traditionally measured using the static method. The dynamic method, via vertical spring-mass oscillator, that uses a stopwatch in order to measure the period of oscillations is also commonly employed. However, this time-measuring technique is prone to human errors and in this paper we…

Costume jewelry beads are employed to demonstrate how a beam of beads are able to transform into a simple pendulum (single bead) where the pendulum length remains constant throughout. These beads are common and inexpensive for instructors, as well as attractive and exciting for students. Beads are removed from the top, keeping the same pendulum…

This article considers a further experimental demonstration of the equations of projectile motion employing the popular video-based motion modeling tool called Tracker. Using a downloaded video--of a free throw attempt by the NBA star Lebron James--from YouTube.com, the primary equations of projectile motion, together with a number of projectile…

Problems of optimization in natural science, technology, economics, and management are of great interest. Students also usually find them intriguing. However, the selection of such problems in introductory undegraduate physics textbooks is very limited and should be broadened. To that end, a model of traffic flow optimization, simple enough for…