In this note, the classical Doppler shift for some accelerated mechanical systems is considered under a common graphical approach. In one dimension, we study uniform accelerated motion and simple harmonic motion. In two dimensions, uniform circular motion and pendular motion are considered. In each case, an elementary treatment shows that the…

An individual harmonic wave (i.e., having a single frequency and wavelength over all time and space) traveling in a loss-free medium has a single constant speed, which is equal to the magnitude of the phase velocity of the wave. However, when a set of different harmonic waves are traveling in the same direction, they interfere to form wave…

Graphs are an important component in physics laboratory reports. We have noticed that our students have difficulty selecting the "scale" and the "starting value" for an axis while generating graphs on graph paper. Recommendations concerning convenient scales and starting values are found in textbooks, laboratory manuals, and…

At the undergraduate level, the composite motion of simple harmonic vibrations has always been the main content of physics as well as several other scientific disciplines. Many textbooks tell us clearly that when the frequency ratio [omega][subscript 1]/[omega][subscript 2] of two perpendicular vibrations is simple integer ratio n[subscript…

In this work, we present an experimental approximation to the study of the phenomenon of radioactivity in secondary schools, taking as an analogy the process of release of carbon dioxide in a carbonated beverage. In this way, we intend to facilitate the approach to the mathematical formalism and to the graphical description of this phenomenon, as…

The ideal gas law, "PV = nRT," is one of the simplest physical laws in nature that is introduced to students as early as in high school and first year in college. In this equation, "P" stands for pressure, "V" is the volume, "n" is the amount expressed in mole, "T" is the temperature in Kelvin…

This study aims to showcase an experiment for introductory physics students that quantitatively describes the relationship between gas pressure, volume, and temperature. For this purpose, an Arduino Uno Microcontroller and BMP180 pressure sensor are used. The BMP180 can also measure temperature, so another temperature sensor is not needed.…

We present a simple experiment that allows us to demonstrate graphically that the intensity of sound waves is proportional to the square of their amplitude, a result that is theoretically analyzed in any introductory wave course but rarely demonstrated empirically. To achieve our goal, we use an audio signal generator that, when connected to a…

Two well-regarded measurements for the expansion rate of the universe disagree, leaving cosmologists very puzzled. It may be that something large has been overlooked in our theory of the Big Bang. This discrepancy is called the Hubble tension and it has led to a very interesting conversation within the cosmology community.

It's not surprising that rainbows have received a great deal of attention: in textbooks, in magazines, and on the web. They are, after all, beautiful, fascinating, occasionally awe-inspiring, even a little mysterious. They are an almost perfect blend of natural beauty and simple physics. Has everything that can be said about rainbows already been…

Two bodies initially at different temperatures gathered into an isolated container exchange heat and reach an equilibrium state with a common final temperature. During the process, the system is out of equilibrium and its intermediate temperature is not well defined. By conceiving a quasi-static process with infinitesimal steps from the initial to…

For several years, I taught a general education course on the Manhattan Project for students majoring in the arts and humanities who needed a physical science credit as a condition of their graduation requirements. As might be imagined, the challenge in teaching this course was to find a balance between quantitative and qualitative content. A…

Throughout time people have been measuring the rising and setting positions of celestial objects with respect to the horizon. The motivation for this paper is to provide a link between mathematical and observational approximations for the Sun's declination (angular distance from the celestial equator). One source had students do an experiment with…

It is common for high school physics teachers to comment on the challenges they face in supporting students' graph drawing skills, knowing their importance for the study of physics. This paper suggests a novel and alternative way to support students to develop their graph drawing skills as well as teach them about sound, frequency, and amplitude.…

Two of the most fundamental skills that students acquire in introductory undergraduate physics laboratory courses are how to accurately plot data and interpret the physical meaning of linear graphs. We redesigned our graphing skills lab with an open-ended approach designed to promote inquiry in graphical analysis and to address specific areas of…