Mechanics of a Simple Bow
|
|
- Blaze Fowler
- 8 years ago
- Views:
Transcription
1 Mechanics of a Simple Bow Mar French, Assistant Professor Brendan Curtis, Undergraduate Student Vinh Pham, Undergraduate Student Department of Mechanical Engineering Technology Purdue University West Lafayette, IN 4797 rmfrench@purdue.edu Abstract The simple bow is one of the first machines made by man. It is still a fascinating device since its simplicity results in complex behavior. The mechanics involved are highly non-linear and sensitive to even small changes in the geometry of the limbs. To experimentally investigate the behavior of simple bows, we made a shooting machine designed to shoot with little variation in results. In addition to experimental results, we show a discrete analytical model that captures the static behavior of the bow. Introduction A bow is simply a device that turns strain energy into inetic energy. The strain energy stored in the limbs (the flexible elements) is converted to both inetic energy in the limbs and inetic energy in the arrow. A simple bow is one that doesn t use pulleys or levers to produce a mechanical advantage. The geometry of a symmetric simple bow is shown in Figure. Figure - Geometry of a Bow Being Drawn
2 Analytical Model We chose to model the bow limbs simply as an assembly of rigid elements connected by linear torsion springs [,]. The geometry of the math model is shown in Figure. Figure - Geometry of Limb Discretization The x and y locations of the th grid point in the limb is given by x x = ; x = Lesin( θj)for n () i = j= y ; y = Le; y = Lecos( θj) + Lefor n () i = where q = and n is the number of grid points in the limb discretization. The notation in Equations () and () becomes very cumbersome when derivatives are introduced. To eep things clear, two intermediate variables are defined j= S = sin θ i (3) C = cos θi (4) The derivatives of S and C with respect to q i are
3 S j C j S = j > ; = cos θi j (5) j C = j > ; =sin θi j (6) j Equations () and () can be more simply written as x = x = ; x= Le Si for n (7) y = ; y = Le ; y = Le Ci + Lefor n (8) For simplicity, I have assumed that the element lengths, L e, are constant. The deformed shape of the bow is found by minimizing the strain energy in the bow limbs using the shape variables θ i as the design variables [3]. The potential energy of the limb is n ( ) PE..= Ki θi θ i (9) where the superscript indicates the angles between the individual elements that are present before the bow is strung. For a straight longbow, θ o is zero for all elements. The deformed shape of the bow limb is that which minimizes the strain energy. Thus, finding the deformed shape can readily be cast as a minimization problem. To avoid the need for specialized optimization software, a Lagrange multiplier approach can be used to minimize the potential energy function [4]. This allows the use of a commonly-available non-linear equation solver to address the minimization problem developed here. The method appends constraints to the objective function to form a Lagrange function. Minimization of this function results in a solution of the constrained minimization problem. For the single constraint problem examined here, the Lagrange function is of the form L = F + λ g () where λ is a constant called a Lagrange multiplier and g is a constraint. The function L is then minimized by setting the gradient of L taen with respect to the design variables and λ equal to zero and solving the resulting system for the design variables and λ. L M L = {} () L n λ where and L F λ g = + () i i i
4 L λ The derivative of the potential energy expression with respect to θ i is = g (3) PE = K i( θi θ i ) θi (4) i The bow can exist statically in three states: unstrung, strung and drawn. Only in the drawn state are any external forces acting on it. The shape of the unstrung bow is nown a priori and defined by the vector {q o }. The shape of the bow when strung is determined by minimizing the total strain energy subject to the constraint that the tip of the limb can be no more than the length of the string, L s, from the x-axis. The constraint is and the derivative with respect to the i th design variable is n g = yn Ls = Le Ci + Le Ls = (5) g n =Le Si (6) There are two possible ways to string a bow. The first is to bend the limbs forward and the second is to bend the limbs bac. Obviously, the limbs bac solution is the desired one (although for an idealized straight longbow, it doesn't really matter). To ensure the correct solution, one can use a limbs-bac shape for the initial design vector. The system of equations to be solved for the stringing problem is f n F g f = + λ = K( θ θ) θ λles = n F g = + λ M = Kn ( θn θn) θn λle Si = n n n f = L C + L L = n e i e s (7) The only change for the drawing problem is the form of the constraint. Once the bow has been strung, a different constraint must be applied, namely that the distance from the tip of the limb to the point at which the string is being drawn must equal the length of the string. This constraint is n n g = yn + ( xs x ) n Ls = Le Ci + Le xs Le Si Ls i + i = (8) = = where x s is the point to which the string is drawn. The derivative with respect to the i th design variable is
5 g n n n Ci Le Ci + Le Le xs Le Si L i i i = + = = = n n Le Ci + Le xs Le Si i + n e S i (9) Missing from the discussion so far is a means for finding the draw weight of the bow for a given draw length. Again, an energy approach seemed simplest. Assuming negligible losses, the strain energy stored in the bow is the integral of the applied force over the distance in which it is applied plus the energy stored during stringing PE = PE + f(x)dx () x Thus, the force required to hold the bow at any point x' is the rate at which potential energy is increasing at that point x d PE x x= x' = f ( x') () Note that for very small models, a Monte-Carlo approach can be used to simply map design space. Figure 3 shows the design space for a two variable problem. The minimum potential energy state, and thus the actual strung shape occurs when θ is approximately deg and θ is approximately 5 degrees. Figure 4 shows the predicted strain energy as a function of draw length. Figure 3 Design Space for -DOF Model
6 Strain Energy (in-lbf) Normalized Strain Energy Strain Energy Vs. Draw Length String:67 in Brace height: in String:7 in Brace height:6.6 in String:64 in Brace height:.5 in Draw Length (in) Figure 4 Calculated Results for Straight Longbow Using 3-DOF Model Experiment Using A Recurve Bow Efficiency is a measure of how much of the energy introduced to a system is transmitted and how much is lost. Not all the inetic energy is in the arrow, a significant amount can be transferred to the limbs as they spring forward. E = KE + KE () strain arrow limbs The expression for bow efficiency is η = E strain m V arrow arrow (3) It's important to note that this is true for any ind of bow. It doesn't matter whether there are pulleys in the system somewhere or not. From an efficiency standpoint, the purpose of the pulleys in a compound bow is to allow the use of shorter, stiffer bending elements. These compact bending elements undergo relatively little motion during, so more of the strain energy is converted into inetic energy in the arrow. Figure 5 shows a measured draw curve for a simple recurve bow. Strain energy the area under the curve. The area under the draw weight curve from 9.5 in (the brace height) to 3" is inch-pounds
7 6 5 Draw Weight (Pounds) Figure 5 Measured Draw Forces For a Recurve Bow Draw Length (Inches) The arrow weighed about 5 grains and the measured arrow velocity at release averaged 66 feet/second. The resulting efficiency was 64.6% Shooting Machine Perhaps the most serious problem in maing measurements on bows is the variation between shots. Even an accomplished archer cannot exactly duplicate the same conditions over a large number of tests. To improve repeatability, we made a simple shooting machine with replaceable limbs as shown in Figure 6. Figure 6 Shooting Machine, Unstrung
8 The string is drawn and held in position with a mechanical release connected to the fixture with a strain gauge lin as shown in Figure 7. This allowed us to measure an accurate draw force curve. Figure 7 Strain Gauge Lin for Shooting Machine The dimensions of the bow were measured and recorded. Then using a strain gage linage, the strain was measured at different draw lengths. The results are summarized in Table. Table Summary of Draw Force Data Strain Energy (in-lbf) Strain Energy (ft-lbf) Position Draw Length (in) strain, ε (in/in) Draw Force (lbf) E E E E E E E E E (draw length measured from string position at no draw) Draw Length from front of bow (in) Draw force was plotted against draw length. This was fit to a linear equation as seen in Figure 8. Strain energy was found by integrating the linear force equation and is shown in Figure 9. Note the strong correlation between the measured strain energy curve and the predicted shapes presented in Figure 4.
9 Force vs Draw 7. y = 3.59x Draw Force (lbf) Draw Length (in) Figure 8 Draw for Curve for Shooting Machine Strain Energy vs Draw Length 7 6 y =.659x x - 7E-6 5 Strain Energy (in-lbf) Draw Length (in) Figure 9 Strain Energy Curve for Shooting Machine
10 The arrow s weight was measured and high speed video was taen of the arrow s path after being fired from full draw. A frame from the video is shown in Figure. From this video, the arrow s velocity, after leaving the string was determined. The results are summarized in Table Table Summary of Shooting Results Weight (grams) Weight (lbm) Velocity (in/sec) Velocity (ft/sec) Velocity (mph) Kinetic Energy (ft-lbf) Kinetic Energy (in-lbf) Arrow This bow s efficiency was determined to be 56.4% which is approximately correct for long bows. Figure Frame From High Speed Video of Arrow Leaving Shooting Machine
11 Summary We have presented an analytical model for static deformation of a simple bow along with experimental data showing qualitative correlation with both a simple recurve bow and a shooting machine. Ongoing wor will replace the low curvature limbs on the shooting wor with ones having a more pronounced recurve and will quantitatively correlate the discrete model with measured results. Acnowledgement The authors gratefully acnowledge the assistance of Tom Kir in this effort, particularly during the construction of the shooting machine. References. Marlow, W.C.; Bow and Arrow Dynamics, American Journal of Physics; Vol. 49, No. 4, April 98.. Klopsteg, P.E.; "Physics of Bows and Arrows"; American Journal of Physics; Vol., No 4, August 943, pp Tauchert, T.R.; "Energy Principles in Structural Mechanics"; Krieger Publishing, Vanderplaats, Garret N.; "Numerical Optimization Techniques For Engineering Design"; McGraw-Hill, New Yor, 984.
HIGH SCHOOL LESSON GUIDE
HIGH SCHOOL LESSON GUIDE THE PHYSICS OF BECOMING AN ARCHERY SUPERHERO GRADE LEVELS - High School 9 12 CONTENT AREA Physical Science UNIT THEME Physics of Archery TOPICS Potential Energy Conversions TIME
More informationThe Technical Archer. Austin Wargo
The Technical Archer Austin Wargo May 14, 2010 Abstract A mathematical model of the interactions between a long bow and an arrow. The model uses the Euler-Lagrange formula, and is based off conservation
More informationBow and Arrow Efficiency
My Pictures\Archery\Bow and Arrow Efficiency 2/16/11 Bow and Arrow Efficiency Richard A. Baugh Introduction People have been shooting bows and arrows at animals, targets and each other for over 5,000 years.
More informationTo provide insight into the physics of arrow flight and show how archers adapt their equipment to maximize effectiveness.
The Science of Archery Godai Katsunaga Purpose To provide insight into the physics of arrow flight and show how archers adapt their equipment to maximize effectiveness. Archery Archery is one of the events
More informationFRICTION, WORK, AND THE INCLINED PLANE
FRICTION, WORK, AND THE INCLINED PLANE Objective: To measure the coefficient of static and inetic friction between a bloc and an inclined plane and to examine the relationship between the plane s angle
More informationThe Mechanics of Arrow Flight upon Release
The Mechanics of Arrow Flight upon Release Lieu, D.K. University of California, Berkeley Kim, Jinho and Kim, Ki Chan Korea National Sport University, Seoul Abstract The dynamic behavior of arrows upon
More informationCompound archery bow asymmetry in the vertical plane
Sports Eng (2012) 15:167 175 DOI 10.1007/s12283-012-0092-9 ORIGINAL ARTICLE Compound archery bow asymmetry in the vertical plane Ihor Zanevskyy Published online: 27 April 2012 Ó The Author(s) 2012. This
More informationEDUH 1017 - SPORTS MECHANICS
4277(a) Semester 2, 2011 Page 1 of 9 THE UNIVERSITY OF SYDNEY EDUH 1017 - SPORTS MECHANICS NOVEMBER 2011 Time allowed: TWO Hours Total marks: 90 MARKS INSTRUCTIONS All questions are to be answered. Use
More informationJump Shot Mathematics Howard Penn
Jump Shot Mathematics Howard Penn Abstract In this paper we exae variations of standard calculus problems in the context of shooting a basketball jump shot. We believe that many students will find this
More informationENERGYand WORK (PART I and II) 9-MAC
ENERGYand WORK (PART I and II) 9-MAC Purpose: To understand work, potential energy, & kinetic energy. To understand conservation of energy and how energy is converted from one form to the other. Apparatus:
More informationEQUIPMENT SET UP RECURVE BOW
EQUIPMENT SET UP RECURVE BOW Archery Australia Inc Coaching and Standards Committee Proudly Sponsored By EQUIPMENT SET UP RECURVE BOW It is important that equipment to be used must be set up correctly
More informationThe elements used in commercial codes can be classified in two basic categories:
CHAPTER 3 Truss Element 3.1 Introduction The single most important concept in understanding FEA, is the basic understanding of various finite elements that we employ in an analysis. Elements are used for
More informationTopics on Archery Mechanics. Joe Tapley
Topics on Archery Mechanics Joe Tapley Topics on Archery Mechanics Introduction The basic physics of archery has in principle been understood for around 80 years. The last topic to be theoretically described
More informationObjectives. Experimentally determine the yield strength, tensile strength, and modules of elasticity and ductility of given materials.
Lab 3 Tension Test Objectives Concepts Background Experimental Procedure Report Requirements Discussion Objectives Experimentally determine the yield strength, tensile strength, and modules of elasticity
More informationSolid Mechanics. Stress. What you ll learn: Motivation
Solid Mechanics Stress What you ll learn: What is stress? Why stress is important? What are normal and shear stresses? What is strain? Hooke s law (relationship between stress and strain) Stress strain
More informationOn the Mechanics of the Arrow: Archer s Paradox 1
On the Mechanics of the Arrow: Archer s Paradox 1 B.W. Kooi and J.A. Sparenberg Abstract In ancient bows the grip of the bow was in the way of the arrow. The arrow needed to get round the bow while being
More informationA QUICK GUIDE TO THE FORMULAS OF MULTIVARIABLE CALCULUS
A QUIK GUIDE TO THE FOMULAS OF MULTIVAIABLE ALULUS ontents 1. Analytic Geometry 2 1.1. Definition of a Vector 2 1.2. Scalar Product 2 1.3. Properties of the Scalar Product 2 1.4. Length and Unit Vectors
More informationKyu-Jung Kim Mechanical Engineering Department, California State Polytechnic University, Pomona, U.S.A.
MECHANICS: STATICS AND DYNAMICS Kyu-Jung Kim Mechanical Engineering Department, California State Polytechnic University, Pomona, U.S.A. Keywords: mechanics, statics, dynamics, equilibrium, kinematics,
More informationwww.mathsbox.org.uk Displacement (x) Velocity (v) Acceleration (a) x = f(t) differentiate v = dx Acceleration Velocity (v) Displacement x
Mechanics 2 : Revision Notes 1. Kinematics and variable acceleration Displacement (x) Velocity (v) Acceleration (a) x = f(t) differentiate v = dx differentiate a = dv = d2 x dt dt dt 2 Acceleration Velocity
More informationB Answer: neither of these. Mass A is accelerating, so the net force on A must be non-zero Likewise for mass B.
CTA-1. An Atwood's machine is a pulley with two masses connected by a string as shown. The mass of object A, m A, is twice the mass of object B, m B. The tension T in the string on the left, above mass
More informationLecture 6. Weight. Tension. Normal Force. Static Friction. Cutnell+Johnson: 4.8-4.12, second half of section 4.7
Lecture 6 Weight Tension Normal Force Static Friction Cutnell+Johnson: 4.8-4.12, second half of section 4.7 In this lecture, I m going to discuss four different kinds of forces: weight, tension, the normal
More informationStructural Axial, Shear and Bending Moments
Structural Axial, Shear and Bending Moments Positive Internal Forces Acting Recall from mechanics of materials that the internal forces P (generic axial), V (shear) and M (moment) represent resultants
More informationBack to Elements - Tetrahedra vs. Hexahedra
Back to Elements - Tetrahedra vs. Hexahedra Erke Wang, Thomas Nelson, Rainer Rauch CAD-FEM GmbH, Munich, Germany Abstract This paper presents some analytical results and some test results for different
More informationChapter 11 Equilibrium
11.1 The First Condition of Equilibrium The first condition of equilibrium deals with the forces that cause possible translations of a body. The simplest way to define the translational equilibrium of
More informationMathematics on the Soccer Field
Mathematics on the Soccer Field Katie Purdy Abstract: This paper takes the everyday activity of soccer and uncovers the mathematics that can be used to help optimize goal scoring. The four situations that
More informationEXPLORING THE TRUE GEOMETRY OF THE INELASTIC INSTANTANEOUS CENTER METHOD FOR ECCENTRICALLY LOADED BOLT GROUPS
EXPLORING THE TRUE GEOMETRY OF THE INELASTIC INSTANTANEOUS CENTER METHOD FOR ECCENTRICALLY LOADED BOLT GROUPS L.S. Muir, P.E., Cives Steel Company, The United States W.A. Thornton, P.E., PhD, Cives Steel
More informationLecture L5 - Other Coordinate Systems
S. Widnall, J. Peraire 16.07 Dynamics Fall 008 Version.0 Lecture L5 - Other Coordinate Systems In this lecture, we will look at some other common systems of coordinates. We will present polar coordinates
More informationTutorial for Assignment #2 Gantry Crane Analysis By ANSYS (Mechanical APDL) V.13.0
Tutorial for Assignment #2 Gantry Crane Analysis By ANSYS (Mechanical APDL) V.13.0 1 Problem Description Design a gantry crane meeting the geometry presented in Figure 1 on page #325 of the course textbook
More informationLinear algebra and the geometry of quadratic equations. Similarity transformations and orthogonal matrices
MATH 30 Differential Equations Spring 006 Linear algebra and the geometry of quadratic equations Similarity transformations and orthogonal matrices First, some things to recall from linear algebra Two
More informationDefinition: A vector is a directed line segment that has and. Each vector has an initial point and a terminal point.
6.1 Vectors in the Plane PreCalculus 6.1 VECTORS IN THE PLANE Learning Targets: 1. Find the component form and the magnitude of a vector.. Perform addition and scalar multiplication of two vectors. 3.
More informationPhysics Notes Class 11 CHAPTER 3 MOTION IN A STRAIGHT LINE
1 P a g e Motion Physics Notes Class 11 CHAPTER 3 MOTION IN A STRAIGHT LINE If an object changes its position with respect to its surroundings with time, then it is called in motion. Rest If an object
More informationSOLID MECHANICS TUTORIAL MECHANISMS KINEMATICS - VELOCITY AND ACCELERATION DIAGRAMS
SOLID MECHANICS TUTORIAL MECHANISMS KINEMATICS - VELOCITY AND ACCELERATION DIAGRAMS This work covers elements of the syllabus for the Engineering Council exams C105 Mechanical and Structural Engineering
More informationCHAPTER 1 ARROW BALLISTICS FROM SINGLE SHOT TO COURSE REQUIREMENTS
CHAPTER 1 ARROW BALLISTICS FROM SINGLE SHOT TO COURSE REQUIREMENTS ARROW FLIGHT - BALLISTICS The Oxford Dictionary defines ballistics as "the science of projectiles." Unfortunately, this leads to thoughts
More informationThe Design of the Bow 1
The Design of the Bow 1 B.W. Kooi Abstract The invention of the bow and arrow probably ranks for social impact with the invention of the art of kindling a fire and the invention of the wheel. It must have
More informationTUNING A LONG BOW. All the illustrations are for the right-handed archer. Our left-handed brethren are clever enough to work it out for themselves.
TUNING A LONG BOW The purpose of this paper is to act as a guide for Long Bow archers and coaches. It contains some rules of thumb, which spells ROT so do not expect them to always be the answer. Good
More informationAP Physics 1 and 2 Lab Investigations
AP Physics 1 and 2 Lab Investigations Student Guide to Data Analysis New York, NY. College Board, Advanced Placement, Advanced Placement Program, AP, AP Central, and the acorn logo are registered trademarks
More informationSlope and Rate of Change
Chapter 1 Slope and Rate of Change Chapter Summary and Goal This chapter will start with a discussion of slopes and the tangent line. This will rapidly lead to heuristic developments of limits and the
More information15.062 Data Mining: Algorithms and Applications Matrix Math Review
.6 Data Mining: Algorithms and Applications Matrix Math Review The purpose of this document is to give a brief review of selected linear algebra concepts that will be useful for the course and to develop
More informationMechanics 1: Conservation of Energy and Momentum
Mechanics : Conservation of Energy and Momentum If a certain quantity associated with a system does not change in time. We say that it is conserved, and the system possesses a conservation law. Conservation
More informationIsaac Newton s (1642-1727) Laws of Motion
Big Picture 1 2.003J/1.053J Dynamics and Control I, Spring 2007 Professor Thomas Peacock 2/7/2007 Lecture 1 Newton s Laws, Cartesian and Polar Coordinates, Dynamics of a Single Particle Big Picture First
More informationB) 286 m C) 325 m D) 367 m Answer: B
Practice Midterm 1 1) When a parachutist jumps from an airplane, he eventually reaches a constant speed, called the terminal velocity. This means that A) the acceleration is equal to g. B) the force of
More informationIntroduction to Mechanical Behavior of Biological Materials
Introduction to Mechanical Behavior of Biological Materials Ozkaya and Nordin Chapter 7, pages 127-151 Chapter 8, pages 173-194 Outline Modes of loading Internal forces and moments Stiffness of a structure
More informationIn-situ Load Testing to Evaluate New Repair Techniques
In-situ Load Testing to Evaluate New Repair Techniques W.J. Gold 1 and A. Nanni 2 1 Assistant Research Engineer, Univ. of Missouri Rolla, Dept. of Civil Engineering 2 V&M Jones Professor, Univ. of Missouri
More informationEquations Involving Lines and Planes Standard equations for lines in space
Equations Involving Lines and Planes In this section we will collect various important formulas regarding equations of lines and planes in three dimensional space Reminder regarding notation: any quantity
More informationElectric Motors and Drives
EML 2322L MAE Design and Manufacturing Laboratory Electric Motors and Drives To calculate the peak power and torque produced by an electric motor, you will need to know the following: Motor supply voltage,
More informationFITA Coach s Manual. RECURVE BOW EQUIPMENT TUNING Module. Intermediate Level
FITA Coach s Manual RECURVE BOW EQUIPMENT TUNING Module Intermediate Level FITA Coaching Manual Intermediate Level Module RECURVE BOW EQUIPMENT TUNING Introduction, to tuning competitive recurve bows There
More informationGoal Seeking in Solid Edge
Goal Seeking in Solid Edge White Paper Goal Seeking in Solid Edge software offers a fast built-in method for solving complex engineering problems. By drawing and dimensioning 2D free-body diagrams, Goal
More information2-1 Position, Displacement, and Distance
2-1 Position, Displacement, and Distance In describing an object s motion, we should first talk about position where is the object? A position is a vector because it has both a magnitude and a direction:
More informationThe Bullet-Block Mystery
LivePhoto IVV Physics Activity 1 Name: Date: 1. Introduction The Bullet-Block Mystery Suppose a vertically mounted 22 Gauge rifle fires a bullet upwards into a block of wood (shown in Fig. 1a). If the
More informationStudy Guide for Mechanics Lab Final
Study Guide for Mechanics Lab Final This study guide is provided to help you prepare for the lab final. The lab final consists of multiple-choice questions, usually 2 for each unit, and 4 work-out problems
More informationPHY231 Section 2, Form A March 22, 2012. 1. Which one of the following statements concerning kinetic energy is true?
1. Which one of the following statements concerning kinetic energy is true? A) Kinetic energy can be measured in watts. B) Kinetic energy is always equal to the potential energy. C) Kinetic energy is always
More informationChapter 7 WORK, ENERGY, AND Power Work Done by a Constant Force Kinetic Energy and the Work-Energy Theorem Work Done by a Variable Force Power
Chapter 7 WORK, ENERGY, AND Power Work Done by a Constant Force Kinetic Energy and the Work-Energy Theorem Work Done by a Variable Force Power Examples of work. (a) The work done by the force F on this
More informationPLANE TRUSSES. Definitions
Definitions PLANE TRUSSES A truss is one of the major types of engineering structures which provides a practical and economical solution for many engineering constructions, especially in the design of
More informationMidterm Exam 1 October 2, 2012
Midterm Exam 1 October 2, 2012 Name: Instructions 1. This examination is closed book and closed notes. All your belongings except a pen or pencil and a calculator should be put away and your bookbag should
More informationChapter. 4 Mechanism Design and Analysis
Chapter. 4 Mechanism Design and Analysis 1 All mechanical devices containing moving parts are composed of some type of mechanism. A mechanism is a group of links interacting with each other through joints
More informationStructural Analysis - II Prof. P. Banerjee Department of Civil Engineering Indian Institute of Technology, Bombay. Lecture - 02
Structural Analysis - II Prof. P. Banerjee Department of Civil Engineering Indian Institute of Technology, Bombay Lecture - 02 Good morning. Today is the second lecture in the series of lectures on structural
More informationAP PHYSICS C Mechanics - SUMMER ASSIGNMENT FOR 2016-2017
AP PHYSICS C Mechanics - SUMMER ASSIGNMENT FOR 2016-2017 Dear Student: The AP physics course you have signed up for is designed to prepare you for a superior performance on the AP test. To complete material
More informationThe Mechanics of Arrow Flight 101 By Daniel Grundman Flex-Fletch
The Mechanics of Arrow Flight 101 By Daniel Grundman Flex-Fletch Thunk! The arrow you just released from your bow has hit its target. Or has it? Due to a number of factors, your arrow may or may not have
More informationIn order to describe motion you need to describe the following properties.
Chapter 2 One Dimensional Kinematics How would you describe the following motion? Ex: random 1-D path speeding up and slowing down In order to describe motion you need to describe the following properties.
More informationRecitation Week 4 Chapter 5
Recitation Week 4 Chapter 5 Problem 5.5. A bag of cement whose weight is hangs in equilibrium from three wires shown in igure P5.4. wo of the wires make angles θ = 60.0 and θ = 40.0 with the horizontal.
More informationAP1 Oscillations. 1. Which of the following statements about a spring-block oscillator in simple harmonic motion about its equilibrium point is false?
1. Which of the following statements about a spring-block oscillator in simple harmonic motion about its equilibrium point is false? (A) The displacement is directly related to the acceleration. (B) The
More informationHomework 8 Solutions
Math 17, Section 2 Spring 2011 Homework 8 Solutions Assignment Chapter 7: 7.36, 7.40 Chapter 8: 8.14, 8.16, 8.28, 8.36 (a-d), 8.38, 8.62 Chapter 9: 9.4, 9.14 Chapter 7 7.36] a) A scatterplot is given below.
More informationOpenFOAM Optimization Tools
OpenFOAM Optimization Tools Henrik Rusche and Aleks Jemcov h.rusche@wikki-gmbh.de and a.jemcov@wikki.co.uk Wikki, Germany and United Kingdom OpenFOAM Optimization Tools p. 1 Agenda Objective Review optimisation
More informationChapter 2. Derivation of the Equations of Open Channel Flow. 2.1 General Considerations
Chapter 2. Derivation of the Equations of Open Channel Flow 2.1 General Considerations Of interest is water flowing in a channel with a free surface, which is usually referred to as open channel flow.
More informationName Class Date. You do twice as much work. b. You lift two identical books one meter above the ground.
Exercises 9.1 Work (pages 145 146) 1. Circle the letter next to the correct mathematical equation for work. work = force distance work = distance force c. work = force distance d. work = force distance
More informationExamples of Scalar and Vector Quantities 1. Candidates should be able to : QUANTITY VECTOR SCALAR
Candidates should be able to : Examples of Scalar and Vector Quantities 1 QUANTITY VECTOR SCALAR Define scalar and vector quantities and give examples. Draw and use a vector triangle to determine the resultant
More informationObjective: Work Done by a Variable Force Work Done by a Spring. Homework: Assignment (1-25) Do PROBS # (64, 65) Ch. 6, + Do AP 1986 # 2 (handout)
Double Date: Objective: Work Done by a Variable Force Work Done by a Spring Homework: Assignment (1-25) Do PROBS # (64, 65) Ch. 6, + Do AP 1986 # 2 (handout) AP Physics B Mr. Mirro Work Done by a Variable
More informationName DATE Per TEST REVIEW. 2. A picture that shows how two variables are related is called a.
Name DATE Per Completion Complete each statement. TEST REVIEW 1. The two most common systems of standardized units for expressing measurements are the system and the system. 2. A picture that shows how
More informationChapter 6 Work and Energy
Chapter 6 WORK AND ENERGY PREVIEW Work is the scalar product of the force acting on an object and the displacement through which it acts. When work is done on or by a system, the energy of that system
More informationSolving Simultaneous Equations and Matrices
Solving Simultaneous Equations and Matrices The following represents a systematic investigation for the steps used to solve two simultaneous linear equations in two unknowns. The motivation for considering
More informationNew approaches in Eurocode 3 efficient global structural design
New approaches in Eurocode 3 efficient global structural design Part 1: 3D model based analysis using general beam-column FEM Ferenc Papp* and József Szalai ** * Associate Professor, Department of Structural
More informationPractice Exam Three Solutions
MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department of Physics Physics 8.01T Fall Term 2004 Practice Exam Three Solutions Problem 1a) (5 points) Collisions and Center of Mass Reference Frame In the lab frame,
More informationOn Motion of Robot End-Effector using the Curvature Theory of Timelike Ruled Surfaces with Timelike Directrix
Malaysian Journal of Mathematical Sciences 8(2): 89-204 (204) MALAYSIAN JOURNAL OF MATHEMATICAL SCIENCES Journal homepage: http://einspem.upm.edu.my/journal On Motion of Robot End-Effector using the Curvature
More informationIntroduction to Engineering System Dynamics
CHAPTER 0 Introduction to Engineering System Dynamics 0.1 INTRODUCTION The objective of an engineering analysis of a dynamic system is prediction of its behaviour or performance. Real dynamic systems are
More informationThe Bending Strength of Pasta
The Bending Strength of Pasta 1.105 Lab #1 Louis L. Bucciarelli 9 September, 2003 Lab Partners: [Name1] [Name2] Data File: Tgroup3.txt On the cover page, include your name, the names of your lab partners,
More informationOptical modeling of finite element surface displacements using commercial software
Optical modeling of finite element surface displacements using commercial software Keith B. Doyle, Victor L. Genberg, Gregory J. Michels, Gary R. Bisson Sigmadyne, Inc. 803 West Avenue, Rochester, NY 14611
More informationSECOND DERIVATIVE TEST FOR CONSTRAINED EXTREMA
SECOND DERIVATIVE TEST FOR CONSTRAINED EXTREMA This handout presents the second derivative test for a local extrema of a Lagrange multiplier problem. The Section 1 presents a geometric motivation for the
More informationa. Bow, arrows, strings and accessories shall be free from sights, marks, blemishes or laminations which could be used for aiming.
a. Bow, arrows, strings and accessories shall be free from sights, marks, blemishes or laminations which could be used for aiming. b. An adjustable arrow rest may be used to control the space between the
More informationPHY231 Section 1, Form B March 22, 2012
1. A car enters a horizontal, curved roadbed of radius 50 m. The coefficient of static friction between the tires and the roadbed is 0.20. What is the maximum speed with which the car can safely negotiate
More informationPrecise Modelling of a Gantry Crane System Including Friction, 3D Angular Swing and Hoisting Cable Flexibility
Precise Modelling of a Gantry Crane System Including Friction, 3D Angular Swing and Hoisting Cable Flexibility Renuka V. S. & Abraham T Mathew Electrical Engineering Department, NIT Calicut E-mail : renuka_mee@nitc.ac.in,
More informationGravitational Potential Energy
Gravitational Potential Energy Consider a ball falling from a height of y 0 =h to the floor at height y=0. A net force of gravity has been acting on the ball as it drops. So the total work done on the
More informationOrbits of the Lennard-Jones Potential
Orbits of the Lennard-Jones Potential Prashanth S. Venkataram July 28, 2012 1 Introduction The Lennard-Jones potential describes weak interactions between neutral atoms and molecules. Unlike the potentials
More informationCosmosWorks Centrifugal Loads
CosmosWorks Centrifugal Loads (Draft 4, May 28, 2006) Introduction This example will look at essentially planar objects subjected to centrifugal loads. That is, loads due to angular velocity and/or angular
More informationPHYSICS 151 Notes for Online Lecture #6
PHYSICS 151 Notes for Online Lecture #6 Vectors - A vector is basically an arrow. The length of the arrow represents the magnitude (value) and the arrow points in the direction. Many different quantities
More informationFinite Element Formulation for Beams - Handout 2 -
Finite Element Formulation for Beams - Handout 2 - Dr Fehmi Cirak (fc286@) Completed Version Review of Euler-Bernoulli Beam Physical beam model midline Beam domain in three-dimensions Midline, also called
More informationSoil Dynamics Prof. Deepankar Choudhury Department of Civil Engineering Indian Institute of Technology, Bombay
Soil Dynamics Prof. Deepankar Choudhury Department of Civil Engineering Indian Institute of Technology, Bombay Module - 2 Vibration Theory Lecture - 8 Forced Vibrations, Dynamic Magnification Factor Let
More informationChapter 3 Falling Objects and Projectile Motion
Chapter 3 Falling Objects and Projectile Motion Gravity influences motion in a particular way. How does a dropped object behave?!does the object accelerate, or is the speed constant?!do two objects behave
More informationWork. Work = Force x parallel distance (parallel component of displacement) F v
Work Work = orce x parallel distance (parallel component of displacement) W k = d parallel d parallel Units: N m= J = " joules" = ( kg m2/ s2) = average force computed over the distance r r When is not
More information22.302 Experiment 5. Strain Gage Measurements
22.302 Experiment 5 Strain Gage Measurements Introduction The design of components for many engineering systems is based on the application of theoretical models. The accuracy of these models can be verified
More informationPrelab Exercises: Hooke's Law and the Behavior of Springs
59 Prelab Exercises: Hooke's Law and the Behavior of Springs Study the description of the experiment that follows and answer the following questions.. (3 marks) Explain why a mass suspended vertically
More informationLecture L6 - Intrinsic Coordinates
S. Widnall, J. Peraire 16.07 Dynamics Fall 2009 Version 2.0 Lecture L6 - Intrinsic Coordinates In lecture L4, we introduced the position, velocity and acceleration vectors and referred them to a fixed
More information9. The kinetic energy of the moving object is (1) 5 J (3) 15 J (2) 10 J (4) 50 J
1. If the kinetic energy of an object is 16 joules when its speed is 4.0 meters per second, then the mass of the objects is (1) 0.5 kg (3) 8.0 kg (2) 2.0 kg (4) 19.6 kg Base your answers to questions 9
More informationRotational Inertia Demonstrator
WWW.ARBORSCI.COM Rotational Inertia Demonstrator P3-3545 BACKGROUND: The Rotational Inertia Demonstrator provides an engaging way to investigate many of the principles of angular motion and is intended
More informationEquivalent Spring Stiffness
Module 7 : Free Undamped Vibration of Single Degree of Freedom Systems; Determination of Natural Frequency ; Equivalent Inertia and Stiffness; Energy Method; Phase Plane Representation. Lecture 13 : Equivalent
More informationComparison of the Response of a Simple Structure to Single Axis and Multiple Axis Random Vibration Inputs
Comparison of the Response of a Simple Structure to Single Axis and Multiple Axis Random Vibration Inputs Dan Gregory Sandia National Laboratories Albuquerque NM 87185 (505) 844-9743 Fernando Bitsie Sandia
More information4 Gravity: A Force of Attraction
CHAPTER 1 SECTION Matter in Motion 4 Gravity: A Force of Attraction BEFORE YOU READ After you read this section, you should be able to answer these questions: What is gravity? How are weight and mass different?
More informationSIMPLIFIED METHOD FOR ESTIMATING THE FLIGHT PERFORMANCE OF A HOBBY ROCKET
SIMPLIFIED METHOD FOR ESTIMATING THE FLIGHT PERFORMANCE OF A HOBBY ROCKET WWW.NAKKA-ROCKETRY.NET February 007 Rev.1 March 007 1 Introduction As part of the design process for a hobby rocket, it is very
More informationINVESTIGATIONS AND FUNCTIONS 1.1.1 1.1.4. Example 1
Chapter 1 INVESTIGATIONS AND FUNCTIONS 1.1.1 1.1.4 This opening section introduces the students to man of the big ideas of Algebra 2, as well as different was of thinking and various problem solving strategies.
More informationChapter 10 Rotational Motion. Copyright 2009 Pearson Education, Inc.
Chapter 10 Rotational Motion Angular Quantities Units of Chapter 10 Vector Nature of Angular Quantities Constant Angular Acceleration Torque Rotational Dynamics; Torque and Rotational Inertia Solving Problems
More information