In a recent article in this journal, Shakur described an interesting problem where a bullet of mass "m" strikes a block of wood of mass "M" and projects the block upward. The same problem was considered earlier by Cowley et al. and others. The main question of interest is whether the block rises to a greater height if it is…

This article describes an experiment that can be done in the classroom in a simple way, with the support of a "homemade" device or as a laboratory practice with the support of PASCO equipment. Through a theory-practice sequence, kinematic and dynamic equations were checked with qualitative and quantitative analysis, emphasizing the…

Adsorption of methylene blue and malachite green was carried out using "Luffa cylindrica" sponges as adsorbing material. We provide a very illustrative exercise about the use of common natural materials requiring little preparation to solve environmental tasks in a routine laboratory situation such as using dyes. In addition, the…

A versatile and portable apparatus was developed to demonstrate exciting visual displays of catalytic phenomena that introduce basic concepts in catalysis, renewable energy, and chemical safety, in order to pique scientific curiosity in a variety of audiences including middle and high school students, undergraduate and graduate students, and the…

Here we present a new undergraduate laboratory that will introduce the concepts of time-resolved spectroscopy and provide insight into the natural time scales on which chemical dynamics occur through direct measurement. A quantitative treatment of the acquired data will provide a deeper understanding of the role of quantum mechanics and various…

In 1972 Christian B. Anfinsen received the Nobel Prize in Chemistry for "…his work on ribonuclease, especially concerning the connection between the amino acid sequence and the biologically active conformation." The understanding of this principle is crucial for physical biochemistry students, since protein folding studies, bio-computing…

A magnetic linear accelerator (or Gauss accelerator) is a device that uses the conversion of magnetic energy into kinetic energy to launch an object with high velocity. A simple experimental implementation consists of a line of steel spheres in which the first one is a permanent magnetic sphere. If another steel ball collides with the magnetic…

One challenge for the introductory physics teacher is incorporating calculus techniques into the laboratory setting. It can be difficult to strike a balance between presenting an experimental task for which calculus is essential and making the mathematics accessible to learners who may be apprehensive about applying it. One-dimensional kinematics…

The cannon boring experiment of Count Rumford, where eight kilograms of water were boiled by metal on metal friction, is investigated. Consideration of this dramatic demonstration can enrich classroom discussions of calorimetry, units of measure, elements, and thermodynamics. A section pertaining to use of the article in the classroom appears…

The motions of Newton's cradle, consisting of several steel balls hanging side-by-side, have been analysed in terms of a sound pulse that travels via points of contact among the balls. This presupposes a focused energy beam. When the pulse reaches the fifth and final ball, the energy disperses and dislocates the ball with a trajectory equivalent…

On July 19, 1969, Senator Edward Kennedy drove his vehicle off a low bridge on Chappaquiddick Island in Massachusetts. The vehicle sank in 2.1 m of water, coming to rest on its roof. According to Kennedy's version of events, he managed to escape from the submerged vehicle without injury, but his female companion, Mary Jo Kopechne, drowned without…

A Unit Operations Laboratory (UOL) is fundamental to undergraduate chemical engineering education. This article discusses a new course structure for the University of Kansas UOL and details for three new experiments covering the fundamentals of vapor-liquid equilibrium, fluid mechanics, and kinetics. Students apply knowledge from these courses as…

KinSim is a research-grade, interactive, user-friendly, open-source, and visual software for kinetics modeling of environmental chemistry and other applications. Students without any computer-programming background and limited knowledge of environmental chemistry can use KinSim, which also includes multiple features and functionality dedicated to…

We present a versatile experimental apparatus for exploring rotational motion through the interplay between the moment of inertia, torque, and rotational kinetic energy of a wheel. The heart of this experiment uses a 3D-printed wheel along with easily accessible stock components that allow for the adjustment of the moment of inertia while keeping…

This paper presents a method to measure the movement of an object from specific locations on a straight line using an iPhone's magnetometer. In this method, called "magnetogate," an iPhone is placed on a moving object (in this case a toy car) and small neodymium magnets are arranged at equal intervals on one side of a straight line. The…