Shawn Kenny, Ph.D., P.Eng. Assistant Professor Faculty of Engineering and Applied Science Memorial University of Newfoundland ENGI 1313 Mechanics I Lecture 01:Course Introduction and General Principles

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 2 ENGI 1313 Resources Textbook  Engineering Mechanics Statics and Dynamics, 11 th Edition R.C. Hibbeler Pearson Prentice Hall (ISBN )

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 3 ENGI 1313 Resources Statics Study Pack  Chapter reviews  Access to Pearson Prentice Hall website wps.prenhall.com/ esm_hibbeler_engmech_11

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 4 ENGI 1313 Resources MUN Engineering Instructor Website  Course information  Professor contact information  Office Hours Mon. & Wed. (3-5PM) Other times can be scheduled by appointment

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 5 ENGI 1313 Resources General Websites  en.wikibooks.org/wiki/Statics   

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 6 Academic & Administrative Policies MUN Engineering Website  Engineering exam policy MUN Website  University regulations  Student policies

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 7 Course Schedule Lectures  Day:Mon., Tue., Wed. & Fri  Time:  Location:IIC2001 No Lectures  Oct. 8 & 9Fall Break  Nov. 12 Remembrance Day

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 8 Planned Lecture Schedule

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 9 Course Perspective Educational Process  Critical thinking  Making mistakes  Asking questions  Learning  Applying knowledge  Engagement  Professional development

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 10 Course Perspective Fundamental Engineering Course  Mechanics  Foundation to build upon Work Ethic  Regular study habits Lecture and tutorial schedule is known  Critical thinking & problem solving…  Critical thinking & problem solving

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 11 Objective of the Lecture Notes to explicitly follow the textbook to provide complement the textbook by providing additional worked examples to occasionally present complementary material that illustrates practical engineering applications of the theory

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 12 Lecture 01 Objectives to introduce field of mechanics to introduce some fundamental concepts to review units of measurement and systems to provide guidance on engineering calculation procedures and analysis

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 13 Introduction to Mechanics Mechanics Rigid Body Mechanics Deformation Mechanics Fluid Mechanics Statics Dynamics This course only examines Rigid Body Mechanics: Statics

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 14 General Principles Statics  Effect of loads on bodies in static equilibrium Balanced loads At rest or under motion at constant velocity

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 15 General Principles Kinematics  Effect of motion without consideration of loads

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 16 General Principles Dynamics  Effect of loads on bodies in motion Unbalanced loads Acceleration

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 17 Brief Historical Perspective Engineering Mechanics and Principles  Geometry  Empirical Societal Applications  Military  Civilian  Shipbuilding

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 18 Simple Machines Inclined plane  Wedge  Screw Lever  Pulley  Wheel and axle

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 19 Simple Machines Inclined Plane

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 20 Simple Machines Lever

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 21 Simple Machines Lever

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 22 Fundamental Concepts Idealizations  Particle Constant mass Negligible size

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 23 Fundamental Concepts Idealizations  Rigid Body Combination of particles Finite size Relative position of particles remain fixed No internal deformation Deformable Body P P Rigid Body P P

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 24 Fundamental Concepts Idealizations  Concentrated Force Load effects acting at a point on a body Load acts on small dimensions relative to body size

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 25 Fundamental Concepts Newton’s Laws of Motion  Basis of classical mechanics  Motion  Momentum Massive, rigid body Empirical Inertial reference frame (no acceleration)

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 26 Fundamental Concepts Newton’s 1 st Law – Inertia  Particle equilibrium Rest Constant velocity  Unbalanced forces External Change in velocity, acceleration F1F1 F2F2 F3F3 V = 0, v

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 27 Fundamental Concepts Newton’s 2 nd Law – Acceleration  Object in motion  Unbalanced external forces  Acceleration Proportional to force magnitude Direction of applied net unbalanced force

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 28 Fundamental Concepts Newton’s 3 rd Law – Reciprocal Action  Action   Reaction To every action there is an equal and opposite reaction Equal force magnitude Opposite force sense or direction

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 29 Fundamental Concepts Newton’s Law of Gravitational Attraction  Point-to-point mass attraction through centers Force  point mass 1 / distance 2

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 30 Fundamental Concepts Weight  Force acting on particle due to gravity  g = acceleration due to gravity Varies altitude, latitude  not absolute Standard is m/s 2

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 31 Fundamental Concepts Physical Quantities  Characteristics Measurement process System of units  Length (L) Distance, size Relative position of points in space  Time (T) Sequence or succession of events  Mass (M) Intrinsic property of matter Relative action between bodies

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 32 Fundamental Concepts Forces  Type Direct contact Electromagnetic Gravitational  Characteristics Magnitude Direction Point of application

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 33 Units of Measurement Standardized Quantity Physical Property  Scientific method  reproducible  Economic and scientific drivers Historical Context  Human body Examples: digit, palm, cubit  Variability Examples: Arabic, Egyptian, Greek, Roman

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 34 Units of Measurement International System of Units  Unified, rational system Units of measurement Decimal system

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 35 Units of Measurement Imperial and US Customary  Similarities and differences  Multiple units of measurement Length  inch, foot, chain, furlong Mass  grain, ounce, pound,  Relatively more complex rules for conversion 12 inches = 1 foot 5280 feet= 1 mile 16 ounces = 1 pound (mass)  Confusion on units Pound force versus pound mass

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 36 Units of Measurement Base Units  Fundamental structure for the system of units SI  meter (m), kilogram (kg), second (s) FPS  foot (ft), pound (lb), second (s)

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 37 Units of Measurement Derived Units  Physical laws  Base units Compound Units  Area, volume QuantitySymbolBase UnitsDimension ForceN kg  m  s -2 M  L  T -2 PressurePa kg  m 2  s -2 M  L 2  T -2 EnergyJ kg  m -1  s -2 M  L -1  T -2

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 38 Engineering Calculations Significant Figures and Rounding  Measurement tools and error Basis of engineering data Precision versus accuracy  Computational tools Numerical precision Constants (e.g. e,  )  Consistent Use Measurement  meters Reporting  millimeters

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 39 Engineering Analysis Problem Statement  Objective  Data and diagrams  Known and unknown quantities Applicable Theory  Assumptions, limitations and constraints Problem Solution  Dimensionally homogeneous, consistent units  Significant figures and rounding Assessment  Engineering judgment, common sense

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 40 Representative Problems Hibbeler (2007) Textbook Study Pack  Review questions 1 to 8 Problem SetDegree of DifficultyEstimated Time 1-1 to 1-16Easy5-10min 1-17 to 1-20Medium10-15min

ENGI 1313 Statics I – Lecture 01© 2007 S. Kenny, Ph.D., P.Eng. 41 References Hibbeler (2007)