If an empty coffee cup is spun on a horizontal surface about a vertical axis in an anti-clockwise direction, then the whole cup rotates slowly backwards, in a clockwise direction, about a vertical axis located outside the cup. Clues to this curious behaviour are presented by comparing it with other spinning objects.

How many vertical jumps does it take to jump off of a rotating merry-go-round (MGR)? The answer is hidden in the expression: "r[subscript n]" = "r[subscript 0]" (1 + ["beta superscript 2") ["superscript n/2"]. When you make a vertical jump on a train moving on a straight line at constant speed (inertial…

Gravity bends light. One can argue this by reasoning that a beam of light should travel in a curved path when viewed from within an accelerating frame of reference, and then invoking Einstein's principle of equivalence, which asserts that the effects observed in an accelerating frame of reference are indistinguishable from the effects observed in…

We will present a problem-solving method for the dynamics of a projectile that has two perpendicular acceleration vectors through rotation of the axes. This methodology of reparameterizing the two-dimensional system simplifies the speed optimization calculus.

An internet poster recently floated the idea that friction with a recently denser interstellar medium causes global warming. Despite its superficially ridiculous nature, refuting this proposition is an interesting quantitative exercise.

We propose a method to measure the speed of sound in air using a motion detector. The experiment is based on the principle of a motion detector used to measure distances. This device measures the time of flight of alternating ultrasonic waves between the observer and the target. By assuming a fixed speed of sound, the time of flight can be…

The standard model of particle physics is the most successful theory describing the behavior of matter and energy in the subatomic realm. However, success doesn't mean it is perfect, and a recent measurement of the mass of a particle called the W boson is puzzling, as it disagrees with theoretical predictions and earlier precise measurements. If…

The center of mass (CM) is an abstract quantity but essential as a reference point used to understand the position and movement of an object or a system of objects. Many researchers have used video recordings to analyze and understand the movement of objects in a system. In a system with colliding objects, the motion can be obtained precisely from…

The use of toys as teaching aids in physics classrooms has a rich history, and the role of play in science education is a well-established line of research. Much of what has been written on the topic has included discussions of specific toys and the implications of using those toys to teach physics. One of the toys from my childhood that seems to…

The electric field inside a uniformly charged long cylindrical shell is a standard example discussed in introductory university physics. The field is zero inside the cylinder; outside of the cylinder, the field behaves like a long wire at the center carrying the same amount of charge per unit length, analogous to that of a uniformly charged…

Teaching upper division statistical physics can often be clouded by the theory and complex examples used. To better help students appreciate the fundamental statistical concepts and how they are connected to thermodynamic principles this paper suggests using a simple abstract model. Using Atkins' Model students can see these ideas clearly…

Experimental results are presented on the collision of a superball with two different wood blocks. The results are in reasonable agreement with a simple collision model where kinetic energy is conserved, but better agreement is obtained if a small loss of kinetic energy is assumed, as observed. The physics is slightly more complicated than the…

A significant approach that should be followed by physics teachers at the secondary education level in order to enhance students' understanding is to highlight the generality of the mathematical procedures that describe different physical phenomena. In this paper, the common procedure that is used to calculate the duration of various physical…

Students' success in physics problem-solving extends beyond conceptual knowledge of physics, relying significantly on their mathematics skills. Understanding the specific contributions of different mathematics skills to physics problem-solving can offer valuable insights for enhancing physics education. Yet such studies are rare, particularly at…

Supporting student participation and learning in STEM involves motivating students to engage in the most effective learning activities. In this article, we study how student motivation interacts with learning activities, and we pay special attention to active learning and the Scandinavian context where participation in learning activities is…