Your name here Principles Of Engineering Digital Notebook Table of Contents • • • • • • • • • • POE Proficiencies Lesson 1.3 Engineering Careers Lesson 2.3 – Excel Data Representation Lesson 4.1 – Mechanisms & Simple Machines Lesson 4.5 – Control Systems ROBO Pro Free Body Diagrams – Practice Problems Activity 5.1a Working with X and Y Components of Vectors Truss Calculations Practice Exam Problems Fluid Power 37 2 POE Proficiencies Lesson 1.1 Engineers as Problem Solvers 1. Students will have an understanding of engineering and be able to identify engineering achievements through history. 2. Students will be able to identify five historical engineering role models, including minorities and women. 3. Students will be able to identify problems for engineers to solve in the future. 4. Students will be able to define attributes associated with being a successful engineer. Lesson 1.2 Engineering Team 5. Understand that an engineering team must work together to solve problems, with each team member having individual and collective responsibilities. 6. Understand the role of out-sourcing in the engineering process, and how effective communication is essential. 7. Understand how gender-bias, racial-bias and other forms of stereotyping and discrimination can adversely affect communications within an engineering team. 8. Understand how ethics influences the engineering process. 9. Understand how social, environmental and financial constraints influence the engineering process. Lesson 1.3 Careers in Engineering 10. Students will have an understanding of the difference between engineering disciplines and job functions. 11. Students will understand the professional and legal responsibilities associated with being an engineer. 12. Students will research and discover the educational requirements to become an engineer. 13. Students will become familiar with an area of engineering by preparing for and conducting an interview with an engineer in that field of engineering. Lesson 2.1 Sketching 14. Students will compose sketches use proper sketching techniques in the solution of design problems. 15. Students will select the appropriate sketching styles for presentation of a design problem to a group. 16. Students will use proper proportioning while producing annotated sketches. Lesson 2.2 Technical Writing 17. Students will plan and compose a written technical report about the research they conduct about a career field in engineering. 18. Students will be able to formulate an organized outline for a technical paper. Lesson 2.3 Data Representation & Presentation 19. Students will be able to design and create tables, charts, and graphs to illustrate data they have collected. 20. Students will evaluate and select an appropriate type of table, chart, or graph to accurately communicate collected data for written work or presentations. 3 POE Proficiencies Lesson 2.4 Oral Presentations 21. Students will design and deliver a presentation utilizing appropriate support materials about research they have conducted. 22. Students will create and assemble support materials to appropriate demonstrate concepts used in their presentations. 23. 23. 24. 25. Lesson 3.1 Design Process Students will compose and diagram the product development lifecycle of an invention of their choice and report findings to the class. Students will trace the history of an invention and evaluate its effects on society and the environment. Students will examine the evolution of an invention to observe and report on how the design process is applied to continuously redesign and improve the product. Lesson 4.1 Mechanisms 26. Students will identify and explain the function of the essential components of a mechanical system on a display they create. 27. Students will create a display of a mechanical system from a household item they disassemble. 28. Students will mathematically explain the mechanical advantage gained and explain the function of the six different types of simple machines in a presentation on the SMET device. 29. Students will apply simple machines to create mechanical systems in the solution of a design problem. Lesson 4.2 Thermodynamics 30. Students will conduct an energy analysis on a section of their home and calculate the heat loss through walls and windows. 31. Students will research and evaluate systems undergoing thermodynamic cycles for efficiency and present findings to the group. 32. Students will give an oral presentation incorporating the first and second laws of thermodynamics, describing the concept and function of a heat engine of their choice. Lesson 4.3 Fluid Systems 33. Students will evaluate and select specific fluid power sources for different functions. 34. Students will create a flow diagram schematic sketch and compare it to an actual fluid power circuit during a presentation to the class. 35. Students will mathematically calculate and explain the work being done by a specific fluid power device as part of an oral presentation. 36. Students will safely demonstrate proper setup and adjustment of a fluid power system. Lesson 4.4 Electrical Systems 37. Students will create schematic drawings to facilitate experimental measurements of electrical circuits. 38. Students will apply ohm’s and watt’s laws in designing safe electrical circuits. 39. Students will appraise community needs and evaluate the impact supplying electrical generation has on their communities. 40. Students will be able to estimate current consumption by a circuit and be able to compare estimates to accurate measurements they perform. 4 POE Proficiencies Lesson 4.5 Control Systems 41. Students will design, diagram and implement a program to control a device they construct to perform a sorting operation. 42. Students will select and apply concepts of mechanical, electrical, and control systems in solving design problems. 43. Students will formulate a plan for evaluating the functioning of their sorting device and to make appropriate changes in design, circuitry or programming. 44. Students will demonstrate and defend their solution to the design problem in an oral presentation to the class. Lesson 5.1 Statics 45. Students will 46. Students will 47. Students will 48. Students will design. mathematically analyze a simple truss to determine types and magnitude of forces supported in the truss. be able to define, describe and analyze the stresses and forces acting on an object. design, construct and test a model bridge to support the greatest amount of weight per gram of bridge mass. prepare and present a mathematical analysis of a truss design as part of a 5 minute oral presentation about their bridge Lesson 5.2 Strength of Materials 49. Students explain the use of factors of safety in the design process. 50. Students will be able to explain the difference between the area of a cross section of an object and the second moment of the area (Moment of Inertia) and predict the relative strength of one shape vs. another. 51. Students will be able to use a computer aided engineering package to analyze a shape. 52. Students will explain the effects that stress has on a material and explain how the material will react. Lesson 6.1 Categories of Materials 53. Students will be able to identify and differentiate the five basic categories of solid engineering materials. 54. Students will be able to compare and contrast the physical properties of organic, metals, polymers, ceramics, and composites. 55. Students will be able to trace the production of raw material to finished product. 56. Students will be able to identify practical applications of each material category to engineered products and processes. 57. Students will be able to collect, analyze, and test samples of the four basic materials. 58. Students will be able to document and present laboratory data related to studies of material classifications. 5 POE Proficiencies Lesson 6.2 Properties of Materials 59. Students will be able to identify and document the properties of materials. 60. Students will be able to design an experiment to identify an unknown material. 61. The student will be able to formulate conclusions through analysis of recorded laboratory test data for presentations in the form of charts, graphs, written, verbal, and multi-media formats. 62. Students will be able to analyze word problems about forces acting on materials. Lesson 6.3 Manufacturing Processes 63. Students will be able to define and state examples of the major categories of Production Processes. 64. Students will be able to analyze a component of a product and describe the processes used in its creation. 65. Students will be able to interpret a drawing and produce a part. 66. Students will give an oral presentation on the production processes used to create products from a category of materials and a demonstration about one of the processes. Lesson 6.4 Quality Control 67. Students will be able to state the difference between mass and weight. 68. Students will be able to utilize a variety of precision measurement tools to measure appropriate dimensions, mass, and weight. 69. Students will be able to understand and explain why companies have a need for quality control and will describe what customers and companies refer to when the term “quality” is used. 70. Students will be able to calculate the mean, median, mode, and standard deviation for a set of data and apply that information to an understanding of quality assurance. 71. Students will be able to explain the difference between process and product control. 72. Students will be able to distinguish between the characteristics of quality in a final product and the control of quality in each step of a process. 73. Students will understand how control charts are used in industry and will be able to predict whether a process is “out of control,” or not by using a control chart. Lesson 6.5 Material Testing 74. Students will be able to describe and safely conduct destructive and non-destructive material testing and will be able to use the data collected through these tests to compute and document mechanical properties. 75. Students will be able to analyze a product that breaks and be able to explain how the material failed. 6 POE Proficiencies Lesson 7.1 Reliability 76. Students will be able to diagram a system and identify the critical components. 77. Students will be able to mathematically estimate chance of failure of a system given information on certain components. 78. Students will list the causes of failure and be able to propose solutions. 79. Students will prepare and defend a position on an ethical engineering dilemma. Lesson 7.2 Case Study 80. Students will research the engineering, legal, social, and ethical issues related to a final design developed in a case study. 81. Students will analyze an engineering failure for the purpose of presenting an aural report which identifies; causes, damage done, design failures, and other areas where the failure has impacted the environment or society. 82. Students will prepare a written report explaining their analysis of an engineering failure. Lesson 8.1 Linear Motion 83. Students will be able to explain the difference between distance traveled and displacement. 84. Students will design and build a device for the purpose of conducting experiments of acceleration, displacement, and velocity. 7 Engineering Careers • • • • • • • • • • Type Name of Career – Type brief description Type Name of Career – Type brief description Type Name of Career – Type brief description Type Name of Career – Type brief description Type Name of Career – Type brief description Type Name of Career – Type brief description Type Name of Career – Type brief description Type Name of Career – Type brief description Type Name of Career – Type brief description Type Name of Career – Type brief description • • • • • • • • • • Type Name of Career – Type brief description Type Name of Career – Type brief description Type Name of Career – Type brief description Type Name of Career – Type brief description Type Name of Career – Type brief description Type Name of Career – Type brief description Type Name of Career – Type brief description Type Name of Career – Type brief description Type Name of Career – Type brief description Type Name of Career – Type brief description 8 Lesson 2.3 – Data Representation and Presentation Key Terms Directions: • Use the Internet to identify the definitions of the terms below. • Add a link to this slide in your table of contents named Key Terms Lesson 2.3– Data Representation and Presentation • (Delete this text box once you get started and stretch the text box below to fill the slide) Bar Chart Cell Chart Data Graph Histogram Line Graph Pictograph Pie Chart Plotting Qualitative Quantitative Spreadsheet Statistics Table 9 Lesson 4.1 – Mechanisms & Simple Machines Key Terms Directions: • Use the Internet to identify the definitions of the terms below. • Add a link to this slide in your table of contents named Lesson 4.1 - Mechanisms • (Delete this text box once you get started and stretch the text box below to fill the slide) Cam Crankshaft Force Friction Gear Gear Train Inclined Plane Lever Linkage Mass Pitch Pulley Screw Simple Machine Compound Machine Spring Sprocket Fulcrum Thread Torque Effort Load Wedge Wheel and Axle Mechanical Advantage 10 Lesson 4.1 – Energy & Work Key Terms Directions: • Use the Internet to identify the definitions of the terms below. • Add a link to this slide in your table of contents named Lesson 4.1 - Mechanisms • (Delete this text box once you get started and stretch the text box below to fill the slide) Work/ Equation Units of Force English - Foot pounds Metric – Newton Power/ Equation Watt Killowatt Energy Chemical Energy Electrical Energy Solar Energy Radiant Energy Potential Energy Kinetic Energy Law of Conservation of Energy Nuclear Energy Efficiency/ Equation 11 Levers (E X LE = R X LR) Load (R) 1 ? Resistance Arm (LR) Effort Arm (LE) Effort (E) 2 feet 6 feet 1 lbs. 4 feet 4 lbs. 2 8 lbs. 3 13 lbs 2 feet 4 50 lbs. 3 feet 5 113 lbs. 2 feet 6 ? 1 foot ? ? 4 lbs. 5 feet ? ? 10 feet 40 lbs. 1 ton Use the GUESS Method to solve the problems in the table above. G 1 G 2 G 3 U U U E E E S S S S S S G 4 G 5 G U U U E E E S S S S S S 6 12 GUESS Method – Wheel and Axle 1. A wheel is used to turn a valve stem on a water valve. If the wheel radius is 1 foot and the axle radius is .5 inches, what is the mechanical advantage of the wheel and axle? G) U) E) S) S) Wheel Radius 1’ Axle Radius .5” 13 GUESS Method – Wheel and Axle 2. How much resistance force can be overcome when an effort of 80 lbs is applied to the wheel of the water valve in problem 1? G) U) E) S) S) Effort 80 lbs. Wheel Radius 1’ Axle Radius .5” 14 GUESS Method – Wheel and Axle 3. What is the linear distance traveled when a 2.5’ diameter wheel makes one revolution? Linear distance of one revolution is equal to the circumference of the wheel. G) U) E) S) S) Dia. = 2.5’ 15 GUESS Method – Wheel and Axle 4. On an automobile how could you increase the distance traveled for each revolution of the axle while keeping bearing friction constant? 16 GUESS Method – Pulley Problems 1. Using a block and tackle pulley system, determine the number of strands that will be needed to lift a weight of 1092 lbs. by applying 80 pounds of force. G) U) E) S) S) 17 GUESS Method – Pulley Problems 2. Using a block and tackle pulley system, with 7 strands and an input force of 45 pounds, what is the maximum weight that can be lifted? G) U) E) S) S) 18 GUESS Method – Inclined Plane 1. Using the diagram below find the force and mechanical advantage. Be sure to show your work and use the GUESS Method. Mechanical Advantage G)’ U) E) S) S) Force G) U) E) S) S) 19 GUESS Method – Inclined Plane 2. Using the diagram below find the mechanical advantage and effort needed to move the object up the inclined plane. Be sure to show your work and use the GUESS Method. Mechanical Advantage G) U) E) S) S) Force G) U) E) S) S) 20 Activity 4.1d Pulley and Gear Problems Unit 4 – Engineering Systems Pulley Problems Use a blank piece of paper to solve for the unknown quantities in the problems below. Use the GUESS Method to show the equations and all work. 22 Solving Problem 1 - Pulleys Identify how you are going to solve for each missing variable using the formulas provided. Where do I start? 1. Start with a problem that you have 3 of the 4 variables given. 2. Let’s start with the Tout. 3. List the variables provided and solve for the missing one. G: D in = 2, D out = 8, T in = 100 U: T out E: Tin/Tout = Din/Dout S: 100/ Tout = 2/8 S: Tout = 400 ft lb Formulas: Win/Wout = Dout/Din Tin/Tout = Din/Dout SR = Win/Wout 23 Solving Problem 1 - Pulleys 400 ft lb Identify how you are going to solve for each missing variable using the formulas provided. What’s next? Now solve for Wout. List the variables provided and solve for the missing one. G: D in = 2, D out = 8, w in = 200 U: Wout E: Win/Wout = Dout/Din S: 200/Wout = 8/2 S: Wout = 50 rpm Formulas: Win/Wout = Dout/Din Tin/Tout = Din/Dout SR = Win/Wout 24 Solving Problem 1 - Pulleys 50 rpm 400 ft lb Identify how you are going to solve for each missing variable using the formulas provided. What’s next? Solve for SR List the variables provided and solve for the missing one. G: w in = 200, Wout = 50 rpm U: SR E: SR = Win/Wout = 200/50 = 4 S: 200/50 = 4 S: Speed ratio = 4 Formulas: Win/Wout = Dout/Din Tin/Tout = Din/Dout SR = Win/Wout Continue this method to solve for each problem. 25 Gear Problems Use a blank piece of paper to solve for the unknown quantities in the problems below. Use the GUESS Method to show the equations and all work. 26 Solving Problem 1 –gEARS There are four unknown variables to solve for. Here is how it is done: G: Nout = 28, Nin = 12 U: GR E: GR = Nout/Nin S: GR = 28/12 = 2.33 S: Gear Ratio = 2.33 G:Win=1800, Nin=12, Nout=28 U:Wout E: Win*Nin = Wout*Nout S: 1800*12=Wout*28 S: Wout=771 rpm G: Win =1800, Wout=771, Din=6 U: Dout E: Win/Wout = Dout /Din S: 1800/771= Dout /6 S: Dout = 14 in G:Tin100, Din=6, Dout=14 U:Tout E:Tin/Tout=Nin/Nout S:100/Tout=12/28 S:Tout = 233 ft lb Formulas (Gears) GR=Input Rate /Output Rate GR=Nout/Nin SR=W in/Wout W in/Wout=Dout/Din Tin/Tout=Din/Dout Nin/Nout=Din/Dout Tin/Tout=Nin/Nout 27 Lesson 4.5 – Control Systems - ROBO Pro Key Terms Directions: • Use the Internet to identify the definitions of the terms below. • Add a link to this slide in your table of contents named Lesson 4.5 – Control Systems - ROBO Pro • (Delete this text box once you get started and stretch the text box below to fill the slide) Series Circuit Parallel Circuit Analog signal Digital signal Switch Loops Variables Transistor Photocell Photoconductive Current Voltage Resistance 28 Fischertechnik Interface 29 Lesson 4.5 – Control Systems - ROBO Pro Function Blocks Directions: • Use the Internet to identify the definitions of the terms below. • Add a link to this slide in your table of contents named Lesson 4.5 – Control Systems - ROBO Pro – Function Blocks • (Delete this text box once you get started and stretch the text box below to fill the slide) What block is this and what does it do? What block is this and what does it do? What block is this and what does it do? What block is this and what does it do? What block is this and what does it do? What block is this and what does it do? 30 Lesson 4.5 – Control Systems - ROBO Pro Function Blocks Directions: • Use the Internet to identify the definitions of the terms below. • Add a link to this slide in your table of contents named Lesson 4.5 – Control Systems - ROBO Pro – Function Blocks • (Delete this text box once you get started and stretch the text box below to fill the slide) What block is this and what does it do? What block is this and what does it do? What block is this and what does it do? 31 Lesson 4.5 – Control Systems - ROBO Pro Command Buttons What does this do? What does this do? What does this do? What does this do? What does this do? 32 Lesson 4.5 – Control Systems - ROBO Pro Activity 4.5c - Basic Programming Add Brief Description of what each program does here. •BP1A: •BP1B: •BP1C: Add ROBO Pro Screen Shot here! 33 Lesson 4.5 – Control Systems - ROBO Pro Activity 4.5d - Basic Programming 2 Add Brief Description of what each program does here. •BP2A: •BP2B: •BP2C: Add ROBO Pro Screen Shot here! 34 Lesson 4.5 – Control Systems - ROBO Pro Activity 4.5e - Basic Programming 2 Add Brief Description of what each program does here. •BP3A Add ROBO Pro Screen Shot here! 35 Lesson 4.5 – Control Systems - ROBO Pro Activity 4.5g - Closed Loop Control 1 Add Brief Description of what each program does here. •45G1: •45G2: Add ROBO Pro Screen Shot here! 36 Fluid Power Introduction Open the Fluid Power Introduction PowerPoint from the assignment log and add your notes from that in this section. Define the following terms: Fluid Power Hydraulics Pneumatics What do the following Fluid Powered Components do?: Reservoir / Receiver Fluid Conductor Pump / Compressor – Valve – Actuator - 37 Fluid Power Physics Define the following terms: add equations were applicable Energy – Energy Transfer – Work – Power – Horsepower – Torque Flow – Rate of Flow – Pressure Law of conservation of energy: Pascal’s Law: Schematic - 38 Fluid Power Schematics Drag the appropriate schematic symbol next to the term in the table below. Component Symbol Vented Reservoir Pressurized Reservoir Rotary Device Pump Variable Pump Fixed Orifice Flow Control Valve Adjustable Orifice Control Valve 39 Fluid Power Schematics Drag the appropriate schematic symbol next to the term in the table below. Component Symbol 3 position valve Free Flow Check Valve Blocked Flow Valve Motor Bi-directional or reversible Motor Motor with a drain line 40 Fluid Power Schematics Drag the appropriate schematic symbol next to the term in the table below. Component Symbol Single Acting Cylinder Double Acting Cylinder Double Rod Cylinder Large Rod Dia. Cylinder 41 Pneumatic Power Properties of Gases Absolute Pressure = Gauge Pressure + Atmospheric Pressure Identify the following terms: Gauge Pressure: Standard Atmospheric Pressure (barometric pressure): Standard atmospheric pressure equals 14.7 lb/in.2 Absolute Pressure (p) (lb/in.2 or psi): Absolute Temperature: 42 Perfect Gas Laws Law – (Add description) Equation (Add Equation) Boyle’s Law - Charles’ Law - Gay-Lussac’s Law - 43 Hydraulic Power Why are Hydraulic Systems more precise than pneumatic systems? What are the key characteristics of a Hydrodynamic System? What are the key characteristics of a Hydrostatic System? 44 The image to the right shows an ammeter being used to measure the current flowing through a circuit. 1. How much resistance does the fischertechnik® lamp provide against the flow of electricity through this circuit? (B –S09) a) 12V b) 2.0A c) 24V d) 6.0Ω 2. What is the power supply voltage if the ammeter (which is wired in series with the circuit) displays a value of 2A every time the momentary switch is pressed? (Accuracy = 0) (B – S09) a) 12V b) 2.0A c) 24V d) 6.0Ω 45 Unit 5 Statics and Strength of Materials-Activity 5.1g Bridge Building Learning Activity #1-Build a Model of a Truss Bridge Directions: • Use the Activity sheet provided to identify the definitions of the terms below. • Add a link to this slide in your table of contents named Learning Activity #1 Bridge Building • (Delete this text box once you get started and stretch the text box below to fill the slide) Truss Pinned Connections Members Gusset Plate Connections Tension Foundation Compression Abutments Structural Engineer Piers Elevation View Geotechnical Engineer Isometric View Through Truss Top Chord Pony Truss Bottom Chord Deck Truss Verticals Diagonals Struts Lateral Bracing Floor Beams 46 Bridge Components 1. 2. 7. 3. 8. 4. 5. 6. 9. 10. 11. 12. 13. 47 Activity 5.1b – Free Body Diagrams Student practice problems Free Body Diagrams Worksheet Problem 1 Draw free body diagrams (force diagrams) for each of the following: What forces need to be identified to draw the free body diagram? What about the normal force of D, G, & H on the spheres? What about the weight of each object? B H G A All of these things need to be taken into consideration. C WB D N WA WC N 49 Free Body Diagrams Worksheet Problem 1 Draw free body diagrams (force diagrams) for circle A: Isolate circle A What forces are in the x direction? What forces are in the y direction? Don’t forget the weight of A! B is acting on A in both the x an y directions! FB B H G A FG A C FN WA D N WA 50 Free Body Diagrams Worksheet Problem 1 What are the sum of the forces on circle A? B has forces in both the x and y directions. FB Here is how we write the equations: FX=0=FG-FBX=0 -FBY FG The sum of the forces in the x direction equals the force of G – force of B in the x direction. FY=0=FN-WA-FBY=0 A -FBX FN W A The sum of the forces in the y direction equals the normal force –the weight of A, – force of B in the y direction. 51 Free Body Diagrams Worksheet Problem 1 Draw free body diagrams (force diagrams) for circle B: Draw each force Isolate circle B B What forces are acting on B from A? H G A C This includes the weight of B. What forces are acting on B from C? Now calculate the sum of all forces. D 52 Free Body Diagrams Worksheet Problem 1 If this object is not accelerating, what are the sum of the forces on circle B? What are the sum of the forces in the X direction? FX= The sum of the forces in the X direction =Force of FA in the x direction – the force of FC in the x direction. What are the sum of the forces in the Y direction? FY= The sum of the forces in the Y direction =Force of FA in the Y direction + the force of FC in the Y direction – the weight of WB. 53 Free Body Diagrams Worksheet Problem 1 Draw free body diagrams (force diagrams) for circle C: Isolate circle C Draw each force B H G What forces are acting on C from B? What forces are acting on C from H? A C What forces are acting on C from D? There is also the weight of C. D Now calculate the sum of all forces. 54 Free Body Diagrams Worksheet Problem 1 If this object is not accelerating, what are the sum of the forces on circle C? What are the sum of the forces in the X direction? FX= What are the sum of the forces in the Y direction? FY= 55 Free Body Diagrams Worksheet Problem 2 Draw a free body diagram for member AB. What about pivot A? What is affecting the weight of AB? Lets start with Cord CB. The cord is pulling on point B Vector FD has forces in both the X and Y directions. Cord C B D A 56 Free Body Diagrams Worksheet Problem 2 diagram for pivot A. Draw a free body The weight of D causes the following forces on pivot A. Cord C B D A 57 Free Body Diagrams Worksheet Problem Draw a free body diagram 2 for the forces on cylinder D. Cord C B D What are the forces in the x direction? What are the forces in the y direction? What about the force of AB? A 58 Free Body Diagrams Worksheet Problem 3 Draw a free body diagram for member AB which is pin connected at A and supported by member BC. C B A Force 59 Truss Calculations Practice Problem Spring 2006 Practice Problem Test C-Spring 2006 #1 To receive full credit on any problem that requires calculations, you must: 1) identify the formula you are using 2) show substitutions 3) state the answer with the correct units. 61 Practice Problem Test C-Spring 2006 #1 1. Study the truss in Figure 1 and its free body diagram in Figure 2, and answer the following questions. a. Draw a point free body diagram for joint C and label all of the given information for that node (assume all member forces are tension). [2 points] b. Calculate the length of truss member BC. (answer precision = 0.000) [3 points] c. Using joint C, determine the magnitude and type of force (tension or compression) that is being carried by truss member BC. (answer precision = 0.0) [4 points] 62 Practice Problem Test C-Spring 2006 #1-A 1. 2. 3. Isolate Point C What forces are acting on C in the X direction? What forces are acting on C in the Y direction? FBCX FAC 30° FBC FBCY C F1 100 lbs 63 Practice Problem Test C-Spring 2006 #1-A 1. Study the truss in Figure 1 and its free body diagram in Figure 2, and answer the following questions. a. Draw a point free body diagram for joint C and label all of the given information for that node (assume all member forces are tension). [2 points] 64 Practice Problem Test C-Spring 2006 #1-B 1. Study the truss in Figure 1 and its free body diagram in Figure 2, and answer the following questions. b. Calculate the length of truss member BC. (answer precision = 0.000) [3 points] Sketch the triangle and label everything you know about it from the illustration and FBD. 4 ft Use the GUESS Method! G: C = 30 °, AC = 4 ft, B = 90 ° A C 30° U: BC E: BC = cosine θACB x AC S: BC = cosine 30° x 4 ft S: BC = 3.464 ft B 65 Activity 5.1a Working with X and Y Components of Vectors Next Concepts • To analyze a truss, we must be able to mathematically relate the angles of a triangle to the lengths of its sides. • Vectors are described with a direction and force • Fx = force in the x (horizontal) direction • FY = force in the y (vertical) direction • N = metric unit for force (pounds) 67 Next 1. Find the x and y components of vector V. To find VX, notice there is a right triangle. The value of the hypotenuse is 5 and the opposite angle is 30. (SOHCAHTOA) Use sine: VX needs to be broken into its X and Y components, let’s solve for X first Y-axis X-axis 30 V=5N VX = 2.5N G = Angle 30, V=5N U = VX E = sin = opposite hypotenuse Vx 5 S = sin 30 = S = VX = 5 * sin 30 = 2.5 Solution Hint: Think of the vector as pointing southeast. You will need to split it up into its y component (pointing south, and its x component (pointing east). 68 Next 1. Find the x and y components of vector y. To find VY, notice there is a right triangle. The value of the hypotenuse is 5, the adjacent angle is 30 and we know the opposite side is 2.5. (SOHCAHTOA) Use cosine: Y-axis G = = 30°, VX=2.5, V=5N, 90° X-axis U = VY E = cos = VY =-4.3N 30 V=5N S = cos 30 = VY adjacent hypotenuse Vy =2.5 5 S = VY = 5 * cos 30 = 4.3 VX = 2.5N Why is this a negative value? 69 Next 2. Find the x and y components of vector W. Can you predict the solution based on Problem 1? Use the GUESS Method to show all work Y-axis X-axis W=5N 30 Solution Hint: Think of the vector as pointing southwest. You will need to split it up into its y component (pointing south, and its x component (pointing west). Next Problem 70 Previous 3. Find the x and y components of vector W. Can you predict the solution based on Problem 1? Use the GUESS Method to show all work Nail 30 30 W=5N 30 30 V=5N F = resultant force Sir Isaac Newton Next Problem 71 Previous 4. Find the x and y components of vector A. Use the GUESS Method to show all work Y-axis A = 50 N 20 X-axis Solution Hint: Think of the vector as pointing northeast. You need to split it up into the y component (pointing north, and the x component pointing east). Next Problem 72 Previous 5. Find the x and y components of vector B. Use the GUESS Method to show all work Y-axis B = 100 N 15 X-axis Solution Hint: Think of the vector as pointing northeast. You need to split it up into the y component (pointing north, and the x component pointing east). Next Problem 73 Previous 6. Two ropes are attached to the screw eye hook in this picture. Robe B is being pulled with a force of 100N at an angle of 15 degrees to the y-axis. Rope A is being pulled with a force of 50 N at an angle of 20 degrees to the x-axis. Use your solutions from Problems 4 and 5 to find x and y components of the resultant force, F: Next Problem 74 Previous 7. Two ropes are attached to the screw eye hook in this shipping crate. Rope B is being pulled with a force of 5200N at an angle of 30 degrees to the x-axis. Rope A is being pulled with a force of 3000N at an angle of 45 degrees to the x-axis. Find the x and y components of the resultant force, F: A = 3000 N 45 30 B = 5200 N Next Problem 75 Previous 8. This plane is suspended from the wires shown. Calculate the resultant forces with the information provided. 1800 lbs. 1484 lbs. 60 45 385 lbs. 90 2300 lbs. 76 Previous Important Key Terms 1.3 Careers in Engineering Engineering Profession: 4.2 Thermodynamics Convection: Conduction: Radiation: R-value: 4.3 Fluid Systems Pneumatic: Hydraulic: Pascal’s Law: Bernoulli’s Law: 4.4 Electrical Systems Series Circuit: Parallel Circuit: Voltage: Current: 77 Important Key Terms 5.1 Statics Torque (Formula/ definition): 5.2 Strength of Materials Moment of inertia: Cross-sectional area: 6.1 Categories of Materials Ferrous: Non-ferrous: Polymer: Organic: 6.3 Production Processes Injection Molder: Milling Machine: Forging: Annealing: 6.5 Material Testing Plastic deformation Brittle material 78 Important Key Terms 6.4 Statics Torque (Formula/ definition): 7.2 Reliability Product Failure: Ethics: 7.2 Case Studies Case Study: Design Brief: 8.1 Linear Motion Velocity: Acceleration: Displacement: 79 Practice Problems Simple Machines 2005 B # 1 Below are two simple machines. In each case the weight of the load is 120 lbs. For each one, identify the type of simple machine (1 pt), the Mechanical Advantage of the device (1 pt), the Effort Force, F, needed to support the weight. (1 pt) Show all Work (1 pt each). (a) Identify the following: • Simple Machine • MA = •E= (b) Identify the following: • Simple Machine • MA = •E= 81 2005 C # 4 The jack pictured below has a ¾-10 screw thread and a 9-inch effort arm. It can lift an object that weighs up to 600 lbs. Calculate the mechanical advantage of this device. [4 points] Picture this as a lever and solve. 82 Study the technical drawing below, and use auto-shapes to fill in the missing center lines and hidden lines in the orthographic views. Assume the circle represents a thru hole. 83 2006 B # 6 2006 B # 7 7a. What class of lever is shown in Figure 5? Justify your answer. Figure 5 7b. How much effort force is needed to balance the 100 lb load? (show work) 84 Study this technical drawing below, and use auto-shapes to fill in the missing center lines and hidden lines in the orthographic views. 2007 B # 7 85 2007 B # 8 8a. What class of lever is shown in Figure 5? Justify your answer. 8b. How much effort force is needed to balance 20.8 pounds of resistance? (answer precision = 0.0) 86