Science and Golf II: Proceedings of the 1994 World Scientific Congress of Golf

By A. J. Cochran; M. R. Farrally | Go to book overview

44

Experimental determination of inertia ellipsoids

S.H. Johnson

Lehigh University, Bethlehem, Pennsylvania, USA

Abstract

This paper presents a method for measuring the elements of the inertia matrix of an irregular rigid body like a golf-club head by use of a simple pendular device. The examples demonstrate the use of the inertia ellipsoid as a means for visualizing and interpreting inertia properties.

Keywords: Inertia Matrix, Inertia Ellipsoid, Clubhead Inertias, Clubhead Moments


1 Introduction

Indirectly, the rules of golf require that clubheads be rigid bodies. As such, the contribution of the club to an impact with a ball is controlled by the face shape, the location of the face relative to the center of mass, the frictional properties of the face, the clubhead mass and the inertia matrix. The inertia matrix represents the dynamic consequences of the arrangement of the clubhead mass. The ellipsoid of inertia is a graphical way to portray an inertia matrix.

The following body axis system is used here:

z-axis: centerline of the hosel

xy-plane: plane of the hosel end

x-axis: a line in the xy plane parallel to the face

y-axis: completes a righthanded coordinate system

The origin of this xyz axis system is at the center of the hosel end. With this axis system, the coordinates of the center of mass will normally be three positive numbers.

An apparatus for determining the coordinates of the center of mass is shown in the photograph, Figure 1. A transverse rod is attached to the device shown and a hanging weight is moved along the rod until static balance is achieved. This allows calculation of the distance from the pivot line to the center of mass. The process is repeated for two mutually perpendicular orientations.

Science and Golf II: Proceedings of the World Scientific Congress of Golf. Edited by A.J. Cochran and M.R. Farrally. Published in 1994 by E & FN Spon, London. ISBN 0 419 18790 1

-290-

Notes for this page

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items
Notes
Cite this page

Cited page

Style
Citations are available only to our active members.
Buy instant access to cite pages or passages in MLA 8, MLA 7, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

(Einhorn 25)

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Note: primary sources have slightly different requirements for citation. Please see these guidelines for more information.

Cited page

Bookmark this page
Science and Golf II: Proceedings of the 1994 World Scientific Congress of Golf
Table of contents

Table of contents

Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this book

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen
Items saved from this book
  • Bookmarks
  • Highlights & Notes
  • Citations
/ 643

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Buy instant access to cite pages or passages in MLA 8, MLA 7, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    Buy instant access to save your work.

    Already a member? Log in now.

    Search by... Author
    Show... All Results Primary Sources Peer-reviewed

    Oops!

    An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.