Unit 3: Engineering Design Pass in your Technical Drawing Lab and your final Paper Mousetrap Instructions. If you are missing either assignment (or both), pass in a piece of paper with your name and missing assignment title on it. “Give me a lever long enough and I shall move the world.” Archimedes http://www.math.rochester.edu/u/faculty/doug/UGpages/archimedes_lever.gif

Classes of Communication Technology Print Graphic Communication Visual, lingual messages that include printed media Photographic Communication Using photographs, slides, or motion pictures to communicate a message Telecommunications Communicating over a distance Technical Graphic Communication Specific information about a product or its parts [REVIEW]

Communication Technology Major Processes: Relief A modeled work that is raised (or lowered) from a flat background. Cuneiform by the Sumerians ~6000 years ago. Wood block printing ~200 C.E. Movable type printing ~1040 C.E. (Gutenberg ~1450) Intaglio (in-tal-yo) ~1430 Rotary printing press ~1843 Lithography (offset printing) ~1796 The source and destination are not on raised surfaces Grease and water do not readily mix A chemical process Most modern books and newspapers Intaglio (in-tal-yo) 2. The plate is covered in ink 3. Excess ink is removed from surface 1. Depressions cut into printing plate Print Graphic Communication 4. Paper placed on plate and compressed 5. Paper is removed and ink has been transferred Low Relief Cuneiform [REVIEW] High Relief

Communication Technology Telecommunication Communicating over a distance Tele – Greek, “far off” Communicare – Latin, “to share” Rely on the principles of electricity and magnetism 2 types: Hardwired systems (telephone, cable, fiber-optic) Broadcast systems (radio and t.v., mobile phones) Point-to-point: One transmitter and one receiver Broadcast: One powerful transmitter to numerous receivers Telecommunications [REVIEW]

Communication Technology Smoke signals and drums Chains of beacons (Middle Ages) Navigation signals Enemy troops approaching Homing pigeons Carrier pigeons used as early as 1150 in Baghdad Olympic victors, Greece; Stock options, Europe Optical telegraph (semaphore, 1792, France) Towers with pivoting shutters Information encoded by the position of the mechanical elements Telecommunications [REVIEW]

Technical Graphic Communication SKETCHES 1 No drawing tools Technical Graphic Communication [REVIEW]

Technical Graphic Communication MULTI-VIEW DRAWINGS 2 Standard Views Sectional Views Auxiliary Views Developments Working Drawings Technical Graphic Communication [REVIEW]

PICTORIAL DRAWINGS [REVIEW] 3 Technical Graphic Communication Show a likeness of an object as viewed by the eye Isometric Perspective Oblique Exploded Assembly Cutaway Pictorial Technical Graphic Communication [REVIEW]

Communication Technology Isometric Section Standard View Development Perspective Oblique Cut-away Pictorial B C A E B C F G D A D E F Communication Technology G [REVIEW]

Technical Graphic Communication TECHNICAL GRAPHICS Which of the following images are parallel projections? Technical Graphic Communication [REVIEW]

Essential Elements of Engineering Thorough understanding of scientific principles Mechanics, Electricity and Magnetism, Thermodynamics, etc. Practical and useful designs Based on design requirements KISS – Keep It Short and Simple Good communication skills Great design is worthless if not effectively communicated ORAL WRITTEN DRAWINGS [REVIEW]

Engineering Communication Info taken and modified from http://trblist.tamu.edu/programs/comm_presentations/tenopir.pdf [REVIEW]

Including 1 problem from front of algebra sheet #2 Technical Writing Good technical writers practice: Planning – know your audience, know your purpose Clarity – avoid jargon, define the unfamiliar Brevity – less is more, most important first, avoid redundancy Simplicity – avoid complexity and use details wisely Word Choice – avoid pronoun overuse (it/this) and avoid excess words Active Voice – more straightforward and strong UNIT 2: Engineering Communication TEST FRIDAY Including 1 problem from front of algebra sheet #2 Technical writing notes taken from http://web.mit.edu/me-ugoffice/communication/technical-writing.pdf [REVIEW]

Unit 3: Engineering Design Topics Covered Force, Energy, Work, Power, and Efficiency Topics in Mechanical Engineering Topics in Electrical Engineering Engineering Design Process Teams and Projects PROJECT: Mechanically Controlled Electromagnetic Crane

FORCE A push, pull, twist (or bend) A vector quantity Magnitude Direction Thrust – increases velocity Drag – decreases velocity Torque – changes rotational speed Units: Newton (N), Pound-force (lbf) http://en.wikipedia.org/wiki/Force Image: http://raanz.org.nz/wiki/uploads/TM/tmfig002.png

Newton’s Laws of Motion Inertia “Objects continue to move in a state of constant velocity unless acted upon by an external net force.” Fnet = ma “An unbalanced force acting on an object will result in the object’s momentum changing over time.” Reciprocal Actions “Forces always occur in action/reaction pairs.” http://en.wikipedia.org/wiki/Force (image as well)

ENERGY Energy Potential Energy Kinetic Energy A scalar quantity The amount of work that is (or can be) performed by a force Potential Energy Energy stored within a physical system with the potential to be converted into other forms of energy (e.g., kinetic, thermal, sound, light) Types: Gravitational, Elastic, Chemical, Electrical, Nuclear Kinetic Energy The energy an object possesses due to its motion “Energy can be transformed, but cannot be created or destroyed.” http://en.wikipedia.org/wiki/Energy http://en.wikipedia.org/wiki/Potential_energy http://en.wikipedia.org/wiki/Kinetic_energy http://en.wikipedia.org/wiki/First_law_of_thermodynamics

WORK Work “The amount of energy transferred to a system by a force acting through a distance.” The change in kinetic energy of a system W = F x d The work done on an object is the product of the component of the force in the direction of the displacement and the magnitude of the displacement. A force does no work if the object doesn’t move Units: Joule (J), Newton-meter (Nm), Foot-pound (ft-lb) http://en.wikipedia.org/wiki/Work_(physics)

POWER (Mechanical) Power “The rate at which work is performed or energy is converted.” The rate of change of work or energy. P = W / t Units: Watt (W), Foot-pound per second (ft-lb/s), Horse power (hp) http://en.wikipedia.org/wiki/Power_(physics) Image: http://www.movingcars.com.au/amusing/one_horsepower.jpg

EFFICIENCY Efficiency When is efficiency 100%? The ratio of the energy delivered by a system to the energy supplied to it. The ratio between the output of a system and the input When is efficiency 100%? Never – 2nd Law of Thermodynamics Some of the input energy is converted to heat, sound, light, etc. Units: Dimensionless or %, Situational EFFICIENCY = x 100% OUTPUT INPUT http://www.merriam-webster.com/dictionary/efficiency IOT Lesson 3-13, portion on Efficiency developed by D. Zolin http://en.wikipedia.org/wiki/Energy_conversion_efficiency

Engineering Problems Equations Problem Solving Process W = F x d P = W / t F = m x a Eff = (output / input) x 100% Problem Solving Process Write Given, Assign Variables, Sketch and Label Diagram Write Formulas / Equations Substitute and Solve Check Answer, THEN Box Answer

Homework Use dimensional reasoning (and the power-law expression) to determine expressions for the terms on the left side of the equations: W = f(F, d) P = f(F, d, t) F = f(m, a) Eff = f(output, input) Complete front side of worksheet by Wednesday’s class