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Engineering Curves – I
Engineering Curves – I 1. Classification 2. Conic sections - explanation 3. Common Definition 4. Ellipse – ( six methods of construction) 5. Parabola – ( Three methods of construction) 6. Hyperbola – ( Three methods of construction ) 7. Methods of drawing Tangents & Normals ( four cases) Engineering Curves – II 1. Classification 2. Definitions 3. Involutes - (five cases) 4. Cycloid 5. Trochoids – (Superior and Inferior) 6. Epic cycloid and Hypo - cycloid 7. Spiral (Two cases) 8. Helix – on cylinder & on cone 9. Methods of drawing Tangents and Normals (Three cases) ENGINEERING CURVES Part- I {Conic Sections} ELLIPSE PARABOLA HYPERBOLA 1.Concentric Circle Method 1.Rectangle Method 1.Rectangular Hyperbola (coordinates given) 2.Rectangle Method 2 Method of Tangents ( Triangle Method) 2 Rectangular Hyperbola 3.Oblong Method (P-V diagram - Equation given) 3.Basic Locus Method 4.Arcs of Circle Method (Directrix – focus) 3.Basic Locus Method (Directrix – focus) 5.Rhombus Metho 6.Basic Locus Method Methods of Drawing (Directrix – focus) Tangents & Normals To These Curves. CONIC SECTIONS ELLIPSE, PARABOLA AND HYPERBOLA ARE CALLED CONIC SECTIONS BECAUSE THESE CURVES APPEAR ON THE SURFACE OF A CONE WHEN IT IS CUT BY SOME TYPICAL CUTTING PLANES. OBSERVE ILLUSTRATIONS GIVEN BELOW.. Ellipse Section Plane Section Plane Hyperbola Through Generators Parallel to Axis. Section Plane Parallel to end generator. COMMON DEFINATION OF ELLIPSE, PARABOLA & HYPERBOLA: These are the loci of points moving in a plane such that the ratio of it’s distances from a fixed point And a fixed line always remains constant. The Ratio is called ECCENTRICITY. (E) A) For Ellipse E<1 B) For Parabola E=1 C) For Hyperbola E>1 Refer Problem nos. -
Plotting the Spirograph Equations with Gnuplot
Plotting the spirograph equations with gnuplot V´ıctor Lua˜na∗ Universidad de Oviedo, Departamento de Qu´ımica F´ısica y Anal´ıtica, E-33006-Oviedo, Spain. (Dated: October 15, 2006) gnuplot1 internal programming capabilities are used to plot the continuous and segmented ver- sions of the spirograph equations. The segmented version, in particular, stretches the program model and requires the emmulation of internal loops and conditional sentences. As a final exercise we develop an extensible minilanguage, mixing gawk and gnuplot programming, that lets the user combine any number of generalized spirographic patterns in a design. Article published on Linux Gazette, November 2006 (#132) I. INTRODUCTION S magine the movement of a small circle that rolls, with- ¢ O ϕ Iout slipping, on the inside of a rigid circle. Imagine now T ¢ 0 ¢ P ¢ that the small circle has an arm, rigidly atached, with a plotting pen fixed at some point. That is a recipe for β drawing the hypotrochoid,2 a member of a large family of curves including epitrochoids (the moving circle rolls on the outside of the fixed one), cycloids (the pen is on ϕ Q ¡ ¡ ¡ the edge of the rolling circle), and roulettes (several forms ¢ rolling on many different types of curves) in general. O The concept of wheels rolling on wheels can, in fact, be generalized to any number of embedded elements. Com- plex lathe engines, known as Guilloch´e machines, have R been used since the XVII or XVIII century for engrav- ing with beautiful designs watches, jewels, and other fine r p craftsmanships. Many sources attribute to Abraham- Louis Breguet the first use in 1786 of Gilloch´eengravings on a watch,3 but the technique was already at use on jew- elry. -
Around and Around ______
Andrew Glassner’s Notebook http://www.glassner.com Around and around ________________________________ Andrew verybody loves making pictures with a Spirograph. The result is a pretty, swirly design, like the pictures Glassner EThis wonderful toy was introduced in 1966 by Kenner in Figure 1. Products and is now manufactured and sold by Hasbro. I got to thinking about this toy recently, and wondered The basic idea is simplicity itself. The box contains what might happen if we used other shapes for the a collection of plastic gears of different sizes. Every pieces, rather than circles. I wrote a program that pro- gear has several holes drilled into it, each big enough duces Spirograph-like patterns using shapes built out of to accommodate a pen tip. The box also contains some Bezier curves. I’ll describe that later on, but let’s start by rings that have gear teeth on both their inner and looking at traditional Spirograph patterns. outer edges. To make a picture, you select a gear and set it snugly against one of the rings (either inside or Roulettes outside) so that the teeth are engaged. Put a pen into Spirograph produces planar curves that are known as one of the holes, and start going around and around. roulettes. A roulette is defined by Lawrence this way: “If a curve C1 rolls, without slipping, along another fixed curve C2, any fixed point P attached to C1 describes a roulette” (see the “Further Reading” sidebar for this and other references). The word trochoid is a synonym for roulette. From here on, I’ll refer to C1 as the wheel and C2 as 1 Several the frame, even when the shapes Spirograph- aren’t circular. -
The Cycloid: Tangents, Velocity Vector, Area, and Arc Length
The Cycloid: Tangents, Velocity Vector, Area, and Arc Length [This is Chapter 2, section 13 of Historical Perspectives for the Reform of Mathematics Curriculum: Geometric Curve Drawing Devices and their Role in the Transition to an Algebraic Description of Functions; http://www.quadrivium.info/mathhistory/CurveDrawingDevices.pdf Interactive applets for the figures can also be found at Mathematical Intentions.] The circle is the curve with which we all have the most experience. It is an ancient symbol and a cultural icon in most human societies. It is also the one curve whose area, tangents, and arclengths are discussed in our mathematics curriculum without the use of calculus, and indeed long before students approach calculus. This discussion can take place, because most people have a lot of experience with circles, and know several ways to generate them. Pascal thought that, second only to the circle, the curve that he saw most in daily life was the cycloid (Bishop, 1936). Perhaps the large and slowly moving carriage wheels of the seventeenth century were more easily observed than those of our modern automobile, but the cycloid is still a curve that is readily generated and one in which many students of all ages easily take an interest. In a variety of settings, when I have mentioned, for example, the path of an ant riding on the side of a bicycle tire, some immediate interest has been sparked (see Figure 2.13a). Figure 2.13a The cycloid played an important role in the thinking of the seventeenth century. It was used in architecture and engineering (e.g. -
The Tautochrone/Brachistochrone Problems: How to Make the Period of a Pendulum Independent of Its Amplitude
The Tautochrone/Brachistochrone Problems: How to make the Period of a Pendulum independent of its Amplitude Tatsu Takeuchi∗ Department of Physics, Virginia Tech, Blacksburg VA 24061, USA (Dated: October 12, 2019) Demo presentation at the 2019 Fall Meeting of the Chesapeake Section of the American Associa- tion of Physics Teachers (CSAAPT). I. THE TAUTOCHRONE A. The Period of a Simple Pendulum In introductory physics, we teach our students that a simple pendulum is a harmonic oscillator, and that its angular frequency ! and period T are given by s rg 2π ` ! = ;T = = 2π ; (1) ` ! g where ` is the length of the pendulum. This, of course, is not quite true. The period actually depends on the amplitude of the pendulum's swing. 1. The Small-Angle Approximation Recall that the equation of motion for a simple pendulum is d2θ g = − sin θ : (2) dt2 ` (Note that the equation of motion of a mass sliding frictionlessly along a semi-circular track of radius ` is the same. See FIG. 1.) FIG. 1. The motion of the bob of a simple pendulum (left) is the same as that of a mass sliding frictionlessly along a semi-circular track (right). The tension in the string (left) is simply replaced by the normal force from the track (right). ∗ [email protected] CSAAPT 2019 Fall Meeting Demo { Tatsu Takeuchi, Virginia Tech Department of Physics 2 We need to make the small-angle approximation sin θ ≈ θ ; (3) to render the equation into harmonic oscillator form: d2θ rg ≈ −!2θ ; ! = ; (4) dt2 ` so that it can be solved to yield θ(t) ≈ A sin(!t) ; (5) where we have assumed that pendulum bob is at θ = 0 at time t = 0. -
The Cycloid Scott Morrison
The cycloid Scott Morrison “The time has come”, the old man said, “to talk of many things: Of tangents, cusps and evolutes, of curves and rolling rings, and why the cycloid’s tautochrone, and pendulums on strings.” October 1997 1 Everyone is well aware of the fact that pendulums are used to keep time in old clocks, and most would be aware that this is because even as the pendu- lum loses energy, and winds down, it still keeps time fairly well. It should be clear from the outset that a pendulum is basically an object moving back and forth tracing out a circle; hence, we can ignore the string or shaft, or whatever, that supports the bob, and only consider the circular motion of the bob, driven by gravity. It’s important to notice now that the angle the tangent to the circle makes with the horizontal is the same as the angle the line from the bob to the centre makes with the vertical. The force on the bob at any moment is propor- tional to the sine of the angle at which the bob is currently moving. The net force is also directed perpendicular to the string, that is, in the instantaneous direction of motion. Because this force only changes the angle of the bob, and not the radius of the movement (a pendulum bob is always the same distance from its fixed point), we can write: θθ&& ∝sin Now, if θ is always small, which means the pendulum isn’t moving much, then sinθθ≈. This is very useful, as it lets us claim: θθ&& ∝ which tells us we have simple harmonic motion going on. -
A Tale of the Cycloid in Four Acts
A Tale of the Cycloid In Four Acts Carlo Margio Figure 1: A point on a wheel tracing a cycloid, from a work by Pascal in 16589. Introduction In the words of Mersenne, a cycloid is “the curve traced in space by a point on a carriage wheel as it revolves, moving forward on the street surface.” 1 This deceptively simple curve has a large number of remarkable and unique properties from an integral ratio of its length to the radius of the generating circle, and an integral ratio of its enclosed area to the area of the generating circle, as can be proven using geometry or basic calculus, to the advanced and unique tautochrone and brachistochrone properties, that are best shown using the calculus of variations. Thrown in to this assortment, a cycloid is the only curve that is its own involute. Study of the cycloid can reinforce the curriculum concepts of curve parameterisation, length of a curve, and the area under a parametric curve. Being mechanically generated, the cycloid also lends itself to practical demonstrations that help visualise these abstract concepts. The history of the curve is as enthralling as the mathematics, and involves many of the great European mathematicians of the seventeenth century (See Appendix I “Mathematicians and Timeline”). Introducing the cycloid through the persons involved in its discovery, and the struggles they underwent to get credit for their insights, not only gives sequence and order to the cycloid’s properties and shows which properties required advances in mathematics, but it also gives a human face to the mathematicians involved and makes them seem less remote, despite their, at times, seemingly superhuman discoveries. -
Hypocycloid Motion in the Melvin Magnetic Universe
Hypocycloid motion in the Melvin magnetic universe Yen-Kheng Lim∗ Department of Mathematics, Xiamen University Malaysia, 43900 Sepang, Malaysia May 19, 2020 Abstract The trajectory of a charged test particle in the Melvin magnetic universe is shown to take the form of hypocycloids in two different regimes, the first of which is the class of perturbed circular orbits, and the second of which is in the weak-field approximation. In the latter case we find a simple relation between the charge of the particle and the number of cusps. These two regimes are within a continuously connected family of deformed hypocycloid-like orbits parametrised by the magnetic flux strength of the Melvin spacetime. 1 Introduction The Melvin universe describes a bundle of parallel magnetic field lines held together under its own gravity in equilibrium [1, 2]. The possibility of such a configuration was initially considered by Wheeler [3], and a related solution was obtained by Bonnor [4], though in today’s parlance it is typically referred to as the Melvin spacetime [5]. By the duality of electromagnetic fields, a similar solution consisting of parallel electric fields can be arXiv:2004.08027v2 [gr-qc] 18 May 2020 obtained. In this paper, we shall mainly be interested in the magnetic version of this solution. The Melvin spacetime has been a solution of interest in various contexts of theoretical high-energy physics. For instance, the Melvin spacetime provides a background of a strong magnetic field to induce the quantum pair creation of black holes [6, 7]. Havrdov´aand Krtouˇsshowed that the Melvin universe can be constructed by taking the two charged, accelerating black holes and pushing them infinitely far apart [8]. -
Cycloid Article(Final04)
The Helen of Geometry John Martin The seventeenth century is one of the most exciting periods in the history of mathematics. The first half of the century saw the invention of analytic geometry and the discovery of new methods for finding tangents, areas, and volumes. These results set the stage for the development of the calculus during the second half. One curve played a central role in this drama and was used by nearly every mathematician of the time as an example for demonstrating new techniques. That curve was the cycloid. The cycloid is the curve traced out by a point on the circumference of a circle, called the generating circle, which rolls along a straight line without slipping (see Figure 1). It has been called it the “Helen of Geometry,” not just because of its many beautiful properties but also for the conflicts it engendered. Figure 1. The cycloid. This article recounts the history of the cycloid, showing how it inspired a generation of great mathematicians to create some outstanding mathematics. This is also a story of how pride, pettiness, and jealousy led to bitter disagreements among those men. Early history Since the wheel was invented around 3000 B.C., it seems that the cycloid might have been discovered at an early date. There is no evidence that this was the case. The earliest mention of a curve generated by a -1-(Final) point on a moving circle appears in 1501, when Charles de Bouvelles [7] used such a curve in his mechanical solution to the problem of squaring the circle. -
The Math in “Laser Light Math”
The Math in “Laser Light Math” When graphed, many mathematical curves are beautiful to view. These curves are usually brought into graphic form by incorporating such devices as a plotter, printer, video screen, or mechanical spirograph tool. While these techniques work, and can produce interesting images, the images are normally small and not animated. To create large-scale animated images, such as those encountered in the entertainment industry, light shows, or art installations, one must call upon some unusual graphing strategies. It was this desire to create large and animated images of certain mathematical curves that led to our design and implementation of the Laser Light Math projection system. In our interdisciplinary efforts to create a new way to graph certain mathematical curves with laser light, Professor Lessley designed the hardware and software and Professor Beale constructed a simplified set of harmonic equations. Of special interest was the issue of graphing a family of mathematical curves in the roulette or spirograph domain with laser light. Consistent with the techniques of making roulette patterns, images created by the Laser Light Math system are constructed by mixing sine and cosine functions together at various frequencies, shapes, and amplitudes. Images created in this fashion find birth in the mathematical process of making “roulette” or “spirograph” curves. From your childhood, you might recall working with a spirograph toy to which you placed one geared wheel within the circumference of another larger geared wheel. After inserting your pen, then rotating the smaller gear around or within the circumference of the larger gear, a graphed representation emerged of a certain mathematical curve in the roulette family (such as the epitrochoid, hypotrochoid, epicycloid, hypocycloid, or perhaps the beautiful rose family). -
Engineering Curves and Theory of Projections
ME 111: Engineering Drawing Lecture 4 08-08-2011 Engineering Curves and Theory of Projection Indian Institute of Technology Guwahati Guwahati – 781039 Distance of the point from the focus Eccentrici ty = Distance of the point from the directric When eccentricity < 1 Ellipse =1 Parabola > 1 Hyperbola eg. when e=1/2, the curve is an Ellipse, when e=1, it is a parabola and when e=2, it is a hyperbola. 2 Focus-Directrix or Eccentricity Method Given : the distance of focus from the directrix and eccentricity Example : Draw an ellipse if the distance of focus from the directrix is 70 mm and the eccentricity is 3/4. 1. Draw the directrix AB and axis CC’ 2. Mark F on CC’ such that CF = 70 mm. 3. Divide CF into 7 equal parts and mark V at the fourth division from C. Now, e = FV/ CV = 3/4. 4. At V, erect a perpendicular VB = VF. Join CB. Through F, draw a line at 45° to meet CB produced at D. Through D, drop a perpendicular DV’ on CC’. Mark O at the midpoint of V– V’. 3 Focus-Directrix or Eccentricity Method ( Continued) 5. With F as a centre and radius = 1–1’, cut two arcs on the perpendicular through 1 to locate P1 and P1’. Similarly, with F as centre and radii = 2– 2’, 3–3’, etc., cut arcs on the corresponding perpendiculars to locate P2 and P2’, P3 and P3’, etc. Also, cut similar arcs on the perpendicular through O to locate V1 and V1’. 6. Draw a smooth closed curve passing through V, P1, P/2, P/3, …, V1, …, V’, …, V1’, … P/3’, P/2’, P1’. -
The Project Gutenberg Ebook #31061: a History of Mathematics
The Project Gutenberg EBook of A History of Mathematics, by Florian Cajori This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at www.gutenberg.org Title: A History of Mathematics Author: Florian Cajori Release Date: January 24, 2010 [EBook #31061] Language: English Character set encoding: ISO-8859-1 *** START OF THIS PROJECT GUTENBERG EBOOK A HISTORY OF MATHEMATICS *** Produced by Andrew D. Hwang, Peter Vachuska, Carl Hudkins and the Online Distributed Proofreading Team at http://www.pgdp.net transcriber's note Figures may have been moved with respect to the surrounding text. Minor typographical corrections and presentational changes have been made without comment. This PDF file is formatted for screen viewing, but may be easily formatted for printing. Please consult the preamble of the LATEX source file for instructions. A HISTORY OF MATHEMATICS A HISTORY OF MATHEMATICS BY FLORIAN CAJORI, Ph.D. Formerly Professor of Applied Mathematics in the Tulane University of Louisiana; now Professor of Physics in Colorado College \I am sure that no subject loses more than mathematics by any attempt to dissociate it from its history."|J. W. L. Glaisher New York THE MACMILLAN COMPANY LONDON: MACMILLAN & CO., Ltd. 1909 All rights reserved Copyright, 1893, By MACMILLAN AND CO. Set up and electrotyped January, 1894. Reprinted March, 1895; October, 1897; November, 1901; January, 1906; July, 1909. Norwood Pre&: J. S. Cushing & Co.|Berwick & Smith.