Principles Of Engineering. Part A

Transcription

1 Principles Of Engineering Final Examination Part A Fall 2007 Student Name: Date: Class Period: Total Points: /40 Converted Score: /50 Page 1 of 11

2 Directions: Circle the letter of the response that best answers the question or completes the statement. Then fill in the Part A answer sheet. Reference Tables are available at the end of the document. 1. Which of the following engineering achievements occurred first? A. Development of the catapult. C. Development of stone bridges that incorporated wood stringers. B. Development of methods to create fire at will. D. Development of the water wheel. 2. Which definition below best describes the engineering profession? A. The art of a good design. C. An interesting career that combines math and science. B. A practical application of math and science. D. The application of math and science to a design. Figure 1a Figure 1b 3. Figure 1a represents a(n) drawing and figure 1b represents a(n) drawing. A. isometric, orthographic C. cabinet oblique, orthographic B. orthographic, isometric D. isometric, cavalier oblique 4. is freehand drawing, which is done without the use of drafting equipment. A. CAD C. Sketching B. Dodging D. Board drafting Figure 2 Page 2 of 11

3 5. The image shown in Figure 2 represents a. A. bar chart. C. line graph. B. pie chart. D. spreadsheet. 6. The first step in the design process is to. A. choose a solution. C. define the problem. B. prepare a design brief. D. develop alternate solutions. Figure 3 7. A wheelbarrow shown in Figure 3 represents what type of simple machine? A. Class 1 Lever A. Class 3 Lever B. Class 2 Lever B. Wheel and Axle Figure 4 8. Given the pulley configuration shown in Figure 4, how many pounds of effort force would a user have to exert on the rope to lift the 60 lb load? A. 15 lbs C. 25 lbs B. 30 lbs D. 20 lbs Figure 5 Page 3 of 11

4 9. A POE student is using the ramp shown in Figure 5 to raise an object 4 feet above the ground. The mechanical advantage of the ramp is. A C. 3.0 B D Figure Study the gear train in Figure 6. The purpose of the center gear is to. A. change the direction of rotation from the input to the C. maintain the direction of rotation from the input to the output gear. output gear. B. decrease the rotational output. D. increase the rotational output. Figure Figure 7 represents a belt driven system. Pully B, which has a diameter of 16 inches, is being driven by pulley A, which has a diameter of 4 inches. If pulley A is spinning at 60 RPMs, then pulley B is spinning at RPMs. A. 240 C. 4 B. 15 D. 64 Page 4 of 11

5 12. In a second class lever, the distance from the effort to the fulcrum is the distance from the load/resistance to the fulcrum. A. less than C. greater than B. less than or equal to D. greater or less than 13. Which of the following methods of heat transfer describes how heat from inside a home is lost to the outside through the walls on a cold day? A. Convection C. Radiation B. Conduction D. R-value 14. A pneumatic device is a machine that derives its mechanical advantage from. A. compressed air. C. gears. B. compressed liquid D. pulleys. 15. states that a force exerted on a fluid will be transferred equally against the walls of that fluid s container. A. Pascal s Law C. Boyle s Law B. Bernoulli s Law D. Charles s Law 16. If one light bulb burns out in a string of lights, and the rest stay lit, it is reasonable to assume that the lights are wired in. A. series C. order B. line D. parallel Figure Study the circuit in Figure 8. Which of the following electrical properties is being measured by the multimeter? A. Resistance C. Current B. Voltage D. RPMs 18. In a control system, provide feedback on the condition of the operating environment. A. computers C. gears B. motors D. sensors Page 5 of 11

6 19. Which of the following digital control devices processes the input information from sensors? A. Microprocessor C. Algorithm B. Variable Resistor D. Flowchart Program Figure If electrical wires are connected to ports 1 and 3 on the limit switch in Figure 9, then the switch will be wired normally-. A. common. C. closed. B. open. D. neutral. 21. Which of the following is a light sensitive input device? A. Lamp C. Phototransistor B. Reed Switch D. Electromagnet 22. A sketch showing a single object with all the surrounding parts removed to expose the external forces is called a. A. stress-strain diagram. C. system diagram. B. load-deflection diagram. D. free body diagram. 23. The torque on an object is calculated using the formula. A. Force / Area. C. Mass * Acceleration. B. Force x Distance. D. Weight * Area. Figure 10 Page 6 of 11

7 24. In the structural system shown in Figure 10, Member B is experiencing. A. compression. C. shear. B. tension. D. torque. 25. Static equilibrium occurs in a truss system when the sum of the is equal to zero. A. velocities C. member lengths B. scalars D. forces and moments 26. When comparing different support beams (made of the same material) for stiffness, it is best to compare their. A. cross-sectional areas. C. moments of inertia. B. height-to-width ratio. D. weights. 27. materials would be attracted to a magnet. A. Ferrous C. Non-ferrous B. Polymer D. Organic Figure Figure 11 shows a 100 lb. normal force being applied to a 12 long x 10 diameter cylinder. What is the resulting compressive stress in the cylinder? A. 10 psi C psi B psi D psi 29. Which of the following manufacturing tools is used to create parts from heated plastic? A. Milling Machine C. Injection Molder B. Lathe D. Drill Press 30. Which of the following manufacturing processes is used to form a piece of metal into a predetermined shape through the application of pressure? A. Turning C. Annealing B. Forging D. Threading Page 7 of 11

8 31. Using a dial caliper, the following seven diameters were obtained for a dogbone aluminum tensile test sample: 0.120, 0.123, 0.121, 0.122, 0.118, and What is the median value for this group of numbers? A C B D Figure The dial caliper in Figure 12 is showing a measurement of inches. A C B D The process of loading a material to the point of failure for the purpose of collecting data on that material s physical properties is known as. A. the offset method. C. statistical process control. B. destructive testing. D. non-destructive testing. 34. A material that experiences very little plastic deformation prior to rupture or fracture would be referred to as a material. A. brittle C. tensile B. polymer D. ductile 35. Poor design, poor construction, and operator error are all reasons for product. A. failure. C. assembly. B. ethics. D. management. Page 8 of 11

9 36. provide a means for analyzing documented events such as engineering disasters, and the ethical dilemmas associated with them. A. Resumes C. Free body diagrams B. Design briefs D. Case studies 37. A free-falling object will experience a constant increase in speed per unit time. This is referred to as due to gravity. A. velocity C. acceleration B. displacement D. force Figure For which of the four launch angles of the ballistic device shown in Figure 13 will the ping pong ball theoretically (no air resistance) go the farthest? A. 20 C. 60 B. 40 D When a projectile is thrown, the component of its initial velocity will remain constant throughout its flight. A. horizontal C. vertical B. Y D. Z 40. Neglecting air resistance, the path that is formed by a projectile with a horizontal component velocity will take the shape of a(n). A. circular curve. C. hyperbolic curve. B. elliptical curve. D. parabolic curve. Page 9 of 11

10 POE Exam Reference Tables Circular Shapes Electrical Systems C = circumference E = voltage C = D = 3.14 E = I R I = current A = r 2 D = diameter R = resistance A = area r = radius Simple Machines MA = R E Lever MA = LE LR Wheel and Axle MA = r w r a Pulley MA = Total number of strands supporting the load Inclined Plane or Wedge MA = L H Screw MA = C Pitch Pitch = 1 TPI MA = mechanical advantage R = resistance force E = effort force LE = length from fulcrum to effort LR = length from fulcrum to resistance L = slope length H = inclined plane height or wedge thickness C = circumference Pitch = screw pitch TPI = threads per inch r w = wheel radius r a = axle radius Statics M = F D SF X = 0 = X (right) + X (left) SF Y = 0 = Y (up) + Y (down) SM = 0 = CCW + CW M = moment about a point F = perpendicular force D = perpendicular distance S = sum of CCW = counter-clockwise moment CW = clockwise moment Right Triangle Ratios sin = opposite hypotenuse cos = adjacent hypotenuse tan = opposite adjacent = angle Page 10 of 11

11 Properties of Materials σ = P A o = L o = (P L) (A o E) E = σ E = ((P 1 -P 2 ) L o ) (( 1-2 ) A o ) = deformation σ = stress = strain E = modulus of elasticity, Young s Modulus P = axial force A o = original area L o = original test length = change in Kinematics V I = initial velocity V IX = initial horizontal velocity V IY = initial vertical velocity = initial trajectory angle g = acceleration due to gravity X = range Note: is measured from the horizontal plane Gear Ratios GR = Input Rate Output Rate GR = N out N in SR = W in W out W in / W out = D out D in T in / T out = D in D out GR = gear ratio N in = number of teeth on driver gear N out = number of teeth on driven gear D in = driver gear diameter, in D out = driven gear diameter, in W in = driver gear speed, rpm W out = driven gear speed, rpm T in = torque of driver gear, ft lbs. T out = torque of driven gear, ft lbs. SR = speed ratio Page 11 of 11