ME 201 Engineering Mechanics: Statics

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ME 201Engineering Mechanics Statics

• Introduction
• BYU-I Learning Model
• Chapter 1
• Newtons Laws of Motion
• Units

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Todays Agenda

• Instructor/Class Introductions
• Syllabus
• BYU-Idaho Learning Model
• Chapter 1

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Instructor Introduction

• Br. Garth Miller, Chairman
• Office Aus 159j
• Class TT 900-1000
• TT 1015-1115

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Instructor Introduction

• Faculty at Ricks since 1993
• Family 10 children
• Mission Bangkok Thailand
• Education BS-BYU, MS-Georgia Tech
• Licensing Professional Engineer
• Prior Employment
• Kaiser Engineers Hanford Richland, Washington
• Chattanooga State Tech Comm Coll Chattanooga,
  TN
• Metropolitan State Collge of Denver Denver,
  Colorado

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Student Introductions

• Name
• Major
• Home town
• Year in School
• Mission/Marriage

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Syllabus

• I-Learn
• Textbook required
• Course Topics
• Outcomes Objectives
• Necessary Equipment
• Calculator
• Mechanical Pencil
• Engineering Paper
• Class Policies and Grading Information

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Evaluation Methods

• Homework Assignments
• Class Preparation Problems
• Homework Problems
• Exams

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Additional Assistance

• Engineering Mechanics Help Lab
• Aus 167
• Tutoring Center
• Mck 272

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ME 201

• True engineering class workload
• Approx 2-3 hours homework for every hour class
• Much easier to keep-up than to catch-up
• New concepts build upon previous concepts
• You will learn by study and also by faith
• Faith requires struggle and stepping out of your
  comfort zone beyond the light

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BYU-Idaho Learning Model

• The challenge before us is to create even more
  powerful and effective learning experiences in
  which students learn by faith. This requires,
  but is more than, teaching by the Spirit. To
  learn by faith, students need opportunities to
  take action.
• (Kim B. Clark)

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BYU-Idaho Learning Model Principles

• Learners and Teachers at BYU-Idaho
• Exercise faith in Christ as a principle of action
  and power
• Understand that true teaching is done by and with
  the Holy Ghost
• Lay hold upon the word of God as found in the
  holy scriptures and in the words of the prophets
  in all disciplines
• Act for themselves and accept responsibility for
  their learning and teaching
• Love, serve, and teach one another

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Intro to Statics

• Mechanics Branch of physical science concerned
  with the state of rest or motion of bodies
  subjected to a force
• 3 Branches
• Rigid Body Mechanics
• Deformable-Body Mechanics
• Fluid Mechanics

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Intro to Statics

• Rigid Body Mechanics consists of 2 areas
• Statics
• Equilibrium of bodies at rest / constant motion
• Dynamics
• Bodies in motion, accelerating, etc.

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Basic Quantities Used in Mechanics

• Length
• Time
• Dynamics only
• Mass
• Related to weight by gravitational constant
• Force
• Push or pull, has magnitude, direction, and point
  of application

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Definitions/Assumptions

• Particle
• Has mass but no size
• Allows problems to be reduced to simpler form
• Rigid Body
• Combination of large number of particles which
  remain fixed after load is applied
• Allows us to ignore material properties and small
  deformations that may occur during our analysis
• Concentrated Force
• Force assumed to act entirely at a point

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Newtons 3 Laws of Motion

• Form the entire basis for rigid body mechanics
• First Law
• A particle originally at rest, or moving in a
  straight line with constant velocity, will remain
  in this state provided the particle is not
  subjected to an unbalanced force.
• Examples

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Newtons 3 Laws of Motion

• Second Law
• A particle acted upon by an unbalanced force F
  experiences an acceleration a that has the same
  direction as the force a magnitude that is
  directly proportional to the force.
• Fma
• Examples

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Newtons 3 Laws of Motion

• Third Law
• The mutual forces of action and reaction between
  two particles are equal, opposite, and collinear.
• Examples

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Newtons Law of Gravitational Attraction

• Two particles of mass (M, m) are mutually
  attracted with equal and opposite forces (F and
  F) of magnitude F

Where r distance between the two particles G
universal constant of gravitation
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Newtons Law of Gravitational Attraction

• For most Engineering Calculations
• Earth is one mass (M)
• At sea level, 45º latitude

let
Substituting Fmg or Wmg

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Units of Measurement
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SI System International

• Force Newton
• W mg
• 1 kg 9.81 m/s2
• 9.81 N

A body of mass of 1 kg has a weight of 9.81 N
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SI Prefixes
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US Customary - English

• Mass Slug
• W mg

Slug
A body of weight 32.2 lb has a mass of 1 slug
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Significant Figures

• Generally 3 or 4 appropriate
• Keep intermediate calculations in calculator
• Round final answer
• Examples
• 4.78 47.8 0.478
• 4780 4.78103

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Conversion of Units

• SI to English, English to SI, etc.
• Key Multiply by 1
• Force 1 lb 4.4482 N
• Length 1 ft .3048 m

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Conversion of Units - Example

• Convert 2 km/h to m/s

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Conversion of Units - Example

• Convert 300 lbsec to SI
• 1 lb 4.448 N

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