A loop-the-loop experiment usually involves a ball rolling around a vertical loop. A different version of the experiment is described where a nut was allowed to slide around a vertical loop. In both experiments there is a large decrease in kinetic energy when the ball or the nut first enters the loop.

A collision of one object with two or more objects is relatively complicated in general, but a simple example is provided by Newton's cradle since all the objects are identical and in line. In the present paper, an experiment is described where a heavy mallet collides head-on with two billiard balls. The two conservation equations indicate that…

The problem of a disc or cylinder initially rolling with slipping on a surface and subsequently transitioning to rolling without slipping is often cited in textbooks. Students struggle to qualitatively understand the difference between kinetic and static frictional forces--i.e., whereas the magnitude of the former is known, that of the latter can…

In this work, a simple rocking pendulum, in a circular arc shape, is presented. The idea is to put a rigid arc on a clean flat surface of glass and leave it to oscillate under the effect of a little impulse. Then, the periodic time of this arc pendulum's motion is experimentally determined. The mathematical analysis of the arc's motion is derived…

The momentum is often used to analyse the dynamics of the motion of an experimental interaction between objects. Meanwhile, the interaction force tends to be challenging to observe and obtain. In this study, a simple video-assisted experiment was used to observe the interaction forces during the interaction of two magnetic objects. The interaction…

The question from the title is raised because in almost all introductory physics courses/textbooks the atmospheric pressure has been attributed to the weight of the column of air from a given level in the atmosphere up to its top. "Air is pressing on air." However the same textbooks, in the chapter on the kinetic theory of gases, tell…

The vertical bounce of a plastic egg was investigated by dropping the egg on a horizontal surface and filming the result with a video camera. If the egg is dropped on one end then it bounces just like a spherical ball. If the top end of the egg is pointing forwards or backwards when it lands on the surface, or if the egg is spinning when it lands,…

We investigate the motion of fidget spinners of different configurations with the help of simple devices. Physical quantities associated with the fidget spinner motion like angular speed, moment of inertia and kinetic energy are determined and compared in different configurations. A configurable modification of the fidget spinners is done to…

A simple experiment for students is to measure the coefficient of restitution (COR) for a vertical bounce on a horizontal surface. In this paper, measurements are presented of the COR for a tennis ball bouncing at an oblique angle on a horizontal surface. Changes in the horizontal and rotation speeds were also measured, by filming the bounce with…

In this paper we describe a simple alternative to the telephone book friction experiment, a classic demonstration where a small force (generated for example by the bending of the outer pages) is amplified by the large number of surfaces in contact, resulting in a huge maximum static friction force that has to be counterbalanced in order to…

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 law of conservation of momentum can be applied to a wide range of processes whether it is the collision of subatomic particles, rocket propulsion, or the recoil of a cannon. In this experiment two technologies, the Arduino microcontroller and a PASCO smart cart, are used to create a movable rubber band launcher. The Arduino microcontroller is…

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…

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…

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.