The determination of the speed of sound in air is a classical experiment, usually performed with a resonance tube apparatus. The measured value can be checked against Eq. (1), which describes the temperature dependence of the speed of sound in dry air. A modern implementation of this speed of sound investigation uses an Arduino Uno microcontroller…

The use of video analysis for the study of motion and forces is well established in the worlds of physics and biomechanics. The issue of parallax error, sometimes referred to as perspective error or scaling error, when videotaping a moving object is known, and the experimenter is often counseled to be "far away." However, "far…

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…

I examined the impact of a self-diagnosis activity on students' conceptual understanding and achievements in physics. This activity requires students to self-diagnose their solutions to problems that they have solved on their own--namely, to identify and explain their errors--and self-score them--that is, assign scores to their solutions--aided by…

Integration of science and mathematics as well as with other disciplines is overarching goal of science education. In spite of its importance, teachers have concerns about mathematical difficulties that their students encounter during their teaching. One of the most common subjects that students have mathematical difficulties was reported as…

At our university, students in introductory physics classes perform a laboratory exercise to measure the range of a projectile fired at an assigned angle. A set of photogates is used to determine the initial velocity of the projectile (the launch velocity). We noticed a systematic deviation between the experimentally measured range and the range…

Early in their study of one-dimensional kinematics, my students build an algebraic model that describes the effects of a rolling ball's (perpendicular) collision with a wall. The goal is for the model to predict the ball's velocity when it returns to a fixed point approximately 50-100 cm from the wall as a function of its velocity as it passes…

In this paper, we show the potential of webcams as precision measuring instruments in a physics laboratory. Various sources of error appearing in 2D coordinate measurements using low-cost commercial webcams are discussed, quantifying their impact on accuracy and precision, and simple procedures to control these sources of error are presented.…