The law of conservation of momentum is a fundamental law of nature. It states that the momentum of an isolated system is conserved. In high school or introductory-level physics courses, for simplicity, teachers and textbooks always use collisions in one dimension as the examples to introduce the concept of conservation of momentum. To solve simple…

Work and mechanical energy is a fundamental topic in introductory physics. Studies in existing literature have shown that students have difficulties in understanding work and mechanical energy, particularly the topic of work-energy theorem. To study students' knowledge integration in learning work and mechanical energy, a conceptual framework…

Chemical kinetics is an important topic that is reinforced across the undergraduate chemistry curriculum, but previous research indicates students tend to have difficulty developing a sophisticated understanding of reaction rate. In this qualitative case study, we characterized how two students conceptualized reaction rate in the context of…

Many introductory physics courses begin with the teaching of motion and kinematics. This naturally leads to the use of constant acceleration equations to solve various problems involving common motions (free fall being a notable example). Students can sometimes get the impression that these equations are the only thing they need to remember in…

Herein we present a modified iodine clock experiment which replaces starch with cellulose paper. This provides the reaction with a white solid surface in which color change can be clearly observed and reduces reagent amounts required to 540 µL per group. After data acquisition, students are required to calculate reaction orders and the reaction…

Herein, we present an experience-based learning approach that uses the COVID-19 pandemics knowledge about virus spread and epidemics to establish an analogy between a simple epidemics model--the SIR model (susceptible--infected--removed), and a second-order autocatalytic reaction with subsequent catalyst deactivation. Our approach provides a…

The themes discussed in this study relate to how students reason about the information encoded in rate constants, which is important for developing a deep understanding of chemical kinetics at the molecular level. This study is part of a larger project centered more generally on students' understanding and use of mathematics in chemical kinetics.…

The aim of this paper is to propose a method for solving head-on elastic collisions, without algebraic complications, to emphasize the use of the fundamental conservations laws. Head-on elastic collisions are treated in many physics textbooks as examples of conservation of momentum and kinetic energy.

Chemical kinetics is a highly quantitative content area that involves the use of multiple mathematical representations to model processes and is a context that is under-investigated in the literature. This qualitative study explored undergraduate student integration of chemistry and mathematics during problem solving in the context of chemical…

The oxidation of iron is an important reaction due to its high economic impact. In this laboratory exploration, the total order of this reaction was determined using commercially available handwarmer packets that rely on the iron-oxygen reaction to generate heat. The active ingredient in the handwarmer packet is iron, which interacts with…

Instead of solving ordinary differential equations (ODEs), the damped simple harmonic motion (SHM) is surveyed qualitatively from basic mechanics and quantitatively by the instrumentality of a graph of velocity against displacement. In this way, the condition b ? [square root]4mk for the occurrence of the non-oscillating critical damping and…

As we typically teach in an introductory mechanics course, choosing a "good" coordinate frame with convenient axes may present a major simplification to a problem. Additionally, knowing some conserved quantities provides an extremely powerful problem-solving tool. While the former idea is typically discussed in the context of…

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…

Halfway through the 2015 AFC Championship game between the New England Patriots and Indianapolis Colts, game officials discovered that the Patriots were using underinflated footballs on their offensive snaps. A controversy ensued because the Patriots had actually supplied these balls to the game's referee just hours before kickoff. Athletes and…

As the topic of relativity is developed in a first-year physics class, there seems to be a tendency to move as quickly as possible to the fascinating ideas set forth in Einstein's special theory of relativity. In this paper we linger a little with the Galilean side of relativity and discuss an intriguing problem and its solution to illustrate a…