The falling temperature of the photosphere with height is responsible for the effect known as limb darkening. The Sun is not equally bright all over the disc. When we observe the Sun towards the limbs, it appears to get darker. Light from the photosphere travels through an absorptive medium. Therefore, one can see only so far into the photosphere.…

Einstein's special theory of relativity includes many non-intuitive and apparently paradoxical conclusions about space and time. One of these is time dilation, the fact that a clock moving relative to an observer runs slower than an identical clock at rest in the observer's reference frame. This is clearly exhibited in the extended mean lifetime…

Studying the dynamics of beams is considered an indispensable field for mechanical and civil engineering students. This paper describes, in detail, the use of smartphones in educational practical works to determine and examine the dynamic characteristics of beams subjected to free vibration. Where the smartphone is equipped with a mobile…

The Leaning Tower is a long-time staple of the demonstration room. It can be traced as far back as apparatus catalogues from the 1850s. Some years ago, while teaching himself how to use a new wood lathe, Thomas B. Greenslade, Jr. made a replica of the original design. With the top removed, the tower is stable, but once the top is added, the line…

Although it originates from the ancient Greeks, optics still arouses a lot of scientific interest, mainly due to the technological innovation associated with it. One of its most interesting applications is related to optical metrology and the characterization of materials through optical techniques. While some of these processes can be explained…

Ampère's law is presented in introductory physics as a relation between the line integral of the magnetic field around a closed loop and the net current crossing any open surface spanning that loop. By allowing the surface to pass between the plates of a charging parallel-plate capacitor, Maxwell realized that this law is incomplete and introduced…

When authoring physics problems, professors may develop an intuition for how much information they need to provide such that the problem has a unique answer and is not over constrained. It is an open question as to whether using intuition leads to a sufficiently broad range of problems. In this paper we discuss a systematic way of authoring…

The objective of this study was to understand behavioral characteristics of creative physicists during their growth period, and we want to use any insight gained to help teachers and parents encourage students' creativity in their everyday life. To do this, the critical incident technique was utilized to extract behavioral traits from six…

National calls to transform undergraduate classrooms highlight the increasingly interdisciplinary nature of science, technology, engineering, and mathematics (STEM). As biologists, we use principles from chemistry and physics to make sense of the natural world. One might assume that scientists, regardless of discipline, use similar principles,…

Investigating student learning and understanding of conceptual physics is a primary research area within physics education research. Multiple quantitative methods have been employed to analyze commonly used mechanics conceptual inventories: the Force Concept Inventory (FCI) and the Force and Motion Conceptual Evaluation (FMCE). Recently,…

Students often use incoherent strategies in their problem solving involving force and motion, as revealed, e.g. when they are asked to draw force diagrams for amusement rides involving circular motion, whether in horizontal or vertical planes. Depending on the questions asked, assignments involving circular motion can reveal different types of…

Pole vaulting, the aim of which is to jump over a crossbar with the help of a long flexible pole, is considered to be one of the most complicated and technically demanding motions in track and field athletics. Pole vault performance is basically influenced by the energy exchange between the vaulter and pole. It depends on the sprinting, jumping…

For many years, Atwood's machine has been used to demonstrate, illustrate, or verify Newton's laws in introductory physics courses. It consists of two objects of different mass that are fastened to the ends of a string that hangs over a pulley. In an idealized situation, one assumes that pulley friction, the string's mass, and changes in the…

Changing acceleration and forces are part of the excitement of a roller coaster ride. According to Newton's second law, F = "m"a, every part of our body must be exposed to a force to accelerate. Since our bodies are not symmetric, the direction of the force matters, and must be accounted for by ride designers. An additional complication…

During the last decade there has been a noticeable increase in the number and use of smartphones around the world, a fact evinced in the latest reports by the Groupe Spéciale Mobile Association (GSMA). Nowadays, 1 in 2 people in the world own and use a smartphone.