European Journal of Physics :: Number of documents found: 23

(8544) The period of a simple pendulum is not 2*pi(L/g)^.5

(8044) The Beverly clock

(8545) The rigid pendulum - an antique but evergreen physical model
    Author: Butikov, Eugene I. :: 1999 vol 20 Year Vol (No) Month (or Chapter/Auction item): 1999 20 :: Pages: 429 - 441
    Comments and/or Abstract > "Abstract. Various kinds of motion of a rigid pendulum (including swinging with arbitrarily large amplitudes and complete revolutions) are investigated both analytically and with the help of computerized simulations. The simulation experiments reveal many interesting peculiarities of this famous physical model and complement the analytical study of the subject in a manner that is mutually reinforcing."

(14261) A demonstration of dry and viscous damping of an oscillating pendulum
    Author: Zonetti L F C :: 1999 vol 20 p 85 Year Vol (No) Month (or Chapter/Auction item): :: Pages: 85 - 88
    Comments and/or Abstract > "Abstract. Damped oscillatory motion is one of the most widely studied movements in physics courses. Despite this fact, dry damped oscillatory motion is not commonly discussed in physics textbooks. In this work, we discuss the dry and viscous damped pendulum, in a teaching experiment that can easily be performed by physics or engineering students."

(8046) A tale of a clock - online at
    Author: Crook, A. W. :: 2001 vol 22 Year Vol (No) Month (or Chapter/Auction item): 2001 22 :: Pages: 549-560
    Comments and/or Abstract > "Abstract. A computer model has been constructed of a long case clock standing on a resilient surface, or within a case of impaired shear stiffness, whereby the head of the clock rocks in response to the swinging of its pendulum. The equations of motion are written in matrix form, and are solved by matrix inversion. The model accounts for the tendency of such a clock to stop when its driving weight has descended to about the level of the bob of the pendulum. The model predicts that the lengthening of the suspension of the weight by insertion of a link would permit the clock to run on until the weight becomes grounded. It also predicts that use of the chiming weight as a resonant absorber, by hanging it from a tuned suspension of fixed length, not only allows such a clock to run for the full term of a wind, but improves the constancy of its rate. The effects of a link, and of the resonant absorber, have been verified experimentally."

(8045) Oscillations with three damping effects
    Author: Wang, Xiao-jun, Schmitt, Chris, & Payne, Marvin :: 2002 vol 23 Year Vol (No) Month (or Chapter/Auction item): 2002 23 :: Pages: 153 - 164
    Comments and/or Abstract > "Abstract. Experiments on oscillatory motion are described with three different damping effects. The first experiment is a physical pendulum whose damping mechanism is due to sliding friction; the second is magnetic resistance due to eddy currents; and the third experiment involves a pendulum setup where air resistance is the dominant factor. These three damping mechanisms yield constant (/||), linear, and quadratic resistances in velocity respectively. Approximation methods are described for treating the three damping effects and a general solution is derived for the damping with a very general velocity dependence. A sonic rangefinder is used to record the oscillatory motions of the pendulums. The experimental measurements and theoretical calculations are in a good agreement."

(8043) The pendulum clock: a venerable dynamical system
    Author: Denny, Mark :: 2002 vol 23 jul Year Vol (No) Month (or Chapter/Auction item): 2002 23 :: Pages: 449-458
    Comments and/or Abstract > "Abstract. The steady-state motion of a weight-driven pendulum clock is shown to be a stable limit cycle. An explicit solution is obtained via Green functions. The pendulum amplitude is found to be a simple function of parameters. The key role played by the anchor escapement is discussed and placed in historical context. "

(14243) Using a digital video camera to examine coupled oscillations
    Author: Greczylo T :: 2002 vol 23 jul Year Vol (No) Month (or Chapter/Auction item): :: Pages: 441-447
    Comments and/or Abstract > "Abstract. In our previous paper (Debowska E, Jakubowicz S and Mazur Z 1999 Eur. J. Phys. 20 89-95), thanks to the use of an ultrasound distance sensor, experimental verification of the solution of Lagrange equations for longitudinal oscillations of the Wilberforce pendulum was shown. In this paper the sensor and a digital video camera were used to monitor and measure the changes of both the pendulum's coordinates (vertical displacement and angle of rotation) simultaneously. The experiments were performed with the aid of the integrated software package COACH 5. Fourier analysis in Microsoft Excel 97 was used to find normal modes in each case of the measured oscillations. Comparison of the results with those presented in our previous paper (as given above) leads to the conclusion that a digital video camera is a powerful tool for measuring coupled oscillations of a Wilberforce pendulum. The most important conclusion is that a video camera is able to do something more than merely register interesting physical phenomena - it can be used to perform measurements of physical quantities at an advanced level."

(8547) Effect of the spherical Earth on a simple pendulum
    Author: Burko, Lior M. :: 2003 vol 24 mar Year Vol (No) Month (or Chapter/Auction item): 2003 24 :: Pages: 125 - 130
    Comments and/or Abstract > "Abstract. We consider the period of a simple pendulum in the gravitational field of the spherical Earth. Effectively, gravity is enhanced compared with the often used flat Earth (FE) approximation, such that the period of the pendulum is shortened. We discuss the FE approximation, and show when the corrections due to the spherical Earth may be of interest."

(9641) Long pendulums in gravitational gradients
    Author: Suits B. H. :: 2006 vol 27 Year Vol (No) Month (or Chapter/Auction item): :: Pages: L7 - L11
    Comments and/or Abstract > "Abstract. Previous results for long pendulums above a spherical Earth are generalized for arbitrary non-uniform gravitational fields in the limit of small oscillation. As is the case for the previous results, gravitational gradients are multiplied by the length of the string even though the string is assumed massless. The effect is shown to arise from the constraint on the motion imposed by the string. The significance of these results for real gradients is discussed."response to article by Burko's analysis of a pendulum swinging in a non-uniform gravity field - e.g. gravity changes slightly as the pendulum moves toward the extent of its swing.

(9642) Foucault pendulum with an ideal elastic suspension string [The]
    Author: Stanovnik A. :: 2006 vol 27 Year Vol (No) Month (or Chapter/Auction item): :: Pages: 205 - 213
    Comments and/or Abstract > "Abstract. It is interesting and instructive to compare the precession of a Foucault pendulum, which has an inextensible suspension string, to the precession of an ideal elastic pendulum, for which the string force is proportional to string length (a harmonic oscillator). For the latter case, a simple derivation is presented of the bob trajectories as seen by the local observer on the rotating earth. It is shown that the initial precession rate is equal to the precession rate of the Foucault pendulum, and that the precession period is equal to the rotation period of the earth. The different precession period of the Foucault pendulum may therefore be seen as a cumulative effect of its inextensible suspension string, which constrains the motion of the bob. It is also shown that the initial angular acceleration of the oscillation plane of the ideal elastic pendulum is opposite for opposite initial azimuth angles. If any such difference were observed for a real Foucault pendulum, it might indicate the presence of effects due to elasticity of the suspension string. Another interesting application of the present derivation would be to the precession of the spring-mass oscillator."

(14260) Controlled damping of a physical pendulum: experiments near critical conditions
    Author: Gonzalez Manuel L :: 2006 vol 27 p 257 Year Vol (No) Month (or Chapter/Auction item): :: Pages: 257 - 264
    Comments and/or Abstract > "Abstract. This paper presents an experimental device for the study of damped oscillatory motion along with three associated experiments. Special emphasis is given on both didactic aspects and the interactivity of the experimental set-up, in order to assist students in understanding fundamental aspects of damped oscillatory motion and allow them to directly compare their experimental results with the well-known theory they can find in textbooks. With this in mind, a physical pendulum was selected with an eddy-current damping system that allows the damping conditions to be controlled with great precision. The three experiments examine accurate control of damping, frequency shift near critical damping and the transition from underdamped to overdamped conditions."

(14259) The sundial problem from a new angle
    Author: Goyder R :: 2006 vol 27 p 413 Year Vol (No) Month (or Chapter/Auction item): :: Pages: 413 - 428
    Comments and/or Abstract > "Abstract. I present the age-old mathematics of the sundial from a new perspective. Standard approaches consider the problem in the Earth frame and focus on spherical geometry. In this work, I apply a more physical approach, based on geometric algebra, to the generalized sundial problem of calculating the position of the tip of the shadow of a gnomon on a flat dial surface, both of which can have arbitrary orientation. This results in both an exact expression for the equation of time and formulae for the shadow tip which reduce to standard results for the special cases of common dial types."

(14244) World pendulum - a distributed remotely controlle laboratory to measure the Earth's gravitational acceleration depending on geographical latitude
    Author: Grober S. :: 2007 vol 28 may Year Vol (No) Month (or Chapter/Auction item): :: Pages: 603 - 613
    Comments and/or Abstract > "Abstract. We suggest that different string pendulums are positioned at different locations on Earth and measure at each place the gravitational acceleration (accuracy Δg ~ 0.01 m s−2). Each pendulum can be remotely controlled via the internet by a computer located somewhere on Earth. The theoretical part describes the physical origin of this phenomenon g(), that the Earth's effective gravitational acceleration g depends on the angle of latitude . Then, we present all necessary formula to deduce g() from oscillations of a string pendulum. The technical part explains tips and tricks to realize such an apparatus to measure all necessary values with sufficient accuracy. In addition, we justify the precise dimensions of a physical pendulum such that the formula for a mathematical pendulum is applicable to determine g() without introducing errors. To conclude, we describe the internet version—the string pendulum as a remotely controlled laboratory. The teaching relevance and educational value will be discussed in detail at the end of this paper including global experimenting, using the internet and communication techniques in teaching and new ways of teaching and learning methods."

(14245) New approaches to data acquisitions in a torsion pendulum experiment
    Author: Jiang Daya :: 2007 vol 28 sep Year Vol (No) Month (or Chapter/Auction item): :: Pages: 977 - 982
    Comments and/or Abstract > "Abstract. In this paper, two simple non-contact and cost-effective methods to acquire data in the student laboratory are applied to investigate the motion of a torsion pendulum. The first method is based on a Hall sensor, while the second makes use of an optical mouse."

(14242) A medieval clock made out of simple materials
    Author: Danese B. :: 2008 vol 29 jul Year Vol (No) Month (or Chapter/Auction item): :: Pages: 799 - 814
    Comments and/or Abstract > "Abstract. A cheap replica of the verge-and-foliot clock has been built from simple materials. It is a didactic tool of great power for physics teaching at every stage of schooling, in particular at university level. An account is given of its construction and its working principles, together with motivated examples of a few activities."

(14262) Extraordinary oscillations of an ordinary forced pendulum
    Author: Butikov, Eugene I. :: 2008 vol 29 jul p 215 Year Vol (No) Month (or Chapter/Auction item): :: Pages: p 215 - 233
    Comments and/or Abstract > "Abstract. Several well-known and newly discovered counterintuitive regular and chaotic modes of the sinusoidally driven rigid planar pendulum are discussed and illustrated by computer simulations. The software supporting the investigation offers many interesting predefined examples that demonstrate various peculiarities of this famous physical model. Plausible physical explanations are suggested for some exotic and unexpected motions. This paper can be useful for graduate and advanced undergraduate students and their instructors. The suggested simulation program can also serve as an exploration-oriented tool for discovering new features of the driven pendulum and gives students an opportunity to perform mini-research projects on their own."

(15315) Analysis of a simple pendulum driven at its suspension point
    Author: Yoshida S. :: vol 26 Year Vol (No) Month (or Chapter/Auction item): :: Pages: 493 - 499
    Comments and/or Abstract > pendulum driven near resonant frequency

(15371) Real-world damping of a physical pendulum
    Author: Bacon M.E. :: vol 26 Year Vol (No) Month (or Chapter/Auction item): :: Pages: 651 - 655
    Comments and/or Abstract > excellent article on pendulum damping digital copy

(15049) Low-cost accelerometers for physics experiments
    Comments and/or Abstract >

(14511) A trigonometric approximation for the tension in the string of a simple pendulum accurate for all amplitudes
    Author: Lima F. M. S. :: vol 30 Year Vol (No) Month (or Chapter/Auction item): :: Pages: 95 - 102
    Comments and/or Abstract >

(14512) An Approximate and analytical solution to the carousel-pendulum problem
    Author: Vial Alexandre :: vol 30 Year Vol (No) Month (or Chapter/Auction item): :: Pages: 75 - 78
    Comments and/or Abstract > pendulum motion on a carousel

(14513) Reply to comment on approximation for the large-angle simple pendulum period
    Author: Belendez A. :: vol 30 Year Vol (No) Month (or Chapter/Auction item): :: Pages: p 83 - 86
    Comments and/or Abstract >