This research aimed to measure the coefficient of restitution (COR) for tennis and golf balls using smartphone sensors. The ball and smartphone were attached at the ends of a long plastic strip: one end was a pivot with the attached smartphone and another end was for the attached ball. The ball on the plastic strip was swung to bounce the ball.…

The compatibility of the Newtonian formulation of mechanical energy and the transformation equations of Galilean relativity is demonstrated for three simple examples of motion treated in most introductory physics courses (free fall, a frictionless inclined plane, and a mass/spring system). Only elementary concepts and mathematics, accessible to…

The aim of this investigation is to compare velocity and power variables during loaded-squat jump (SJ[subscript Loaded]) exercise of national athletes dealing with different sports branches and to identify whether velocity and power parameters become different or not according to branches. In accordance with this purpose, a total of 36 national…

In an article in this journal, it was shown that air resistance could never be a significant source of error in typical free-fall experiments in introductory physics laboratories. Since projectile motion is the two-dimensional version of the free-fall experiment and usually follows the former experiment in such laboratories, it seemed natural to…

Most rockets convert the energy stored in their propellant mass into the mechanical energy required to expel it as exhaust. The 'rocket equation', which describes how a rocket's speed changes with mass, is usually derived by assuming that this fuel is expelled at a constant relative velocity. However, this is a poor assumption for cases where the…

In most high school physics classes, gravity is described as an attractive force between two masses as formulated by Newton over 300 years ago. Einstein's general theory of relativity implies that gravitational effects are instead the result of a "curvature" of space-time. However, explaining why things fall without resorting to Newton's…

Students often struggle to understand the independence of velocity vectors in two-dimensional motion. Despite seeing classic projectile demonstrations, it is probably not obvious to most new students why the path of motion is parabolic. Likewise, first-year students might not predict that the path of motion is linear in two-dimensional vector…

Models that are used to predict and explain phenomena related to molecular vibration and rotation are ubiquitous in physical chemistry, and are of importance in many related fields. Yet, little work has been done to characterize student use and application of these models. We describe the results of a multi-year, multi-institutional qualitative…

Many studies have examined the structure and properties of the Force Concept Inventory (FCI); however, far less research has investigated the Force and Motion Conceptual Evaluation (FMCE). This study applied Multidimensional Item Response Theory (MIRT) to a sample of N = 4528 FMCE post-test responses. Exploratory factor analysis showed that 5, 9,…

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…

This work reports a rudimentary approach to teach and measure the kinetic friction coefficient using a smartphone that can effectively be employed for teaching purposes. More specifically, the kinetic friction coefficient, which is rather difficult to teach and measure, between various surfaces was determined by two different approaches using the…

An introduction to digital stochastic simulations for modeling a variety of physical and chemical processes is presented. Despite the importance of stochastic simulations in chemistry, the prevalence of turn-key software solutions can impose a layer of abstraction between the user and the underlying approach obscuring the methodology being…

This study aimed to expand PDEODE*E Tasks with the Think-Pair-Share model for reconstructing students' misconceptions on work and energy. The PDEODE*E Tasks with Think-Pair-Share model implemented for students who had not taught the concept of work and energy. The participants include 36 students of tenth grade (22 girls and 14 boys, whose ages…

A novel method of measuring the coefficients of kinetic and rolling friction is proposed. The method is simple to implement and reliable. Samples of measurements and calculations are presented.

A simple throwing task is described to illustrate various aspects of projectile motion. The task was to throw a tennis ball in a waste paper bin about 2 m away. Success depends on skill, but it also depends on the physics of the problem. If the ball is thrown underarm, then success depends primarily on the throw speed, which must be controlled to…