Problem Set Machine Design Day 1 PDF

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This file is only for viewing.ALCORCON ENGINEERING REVIEW CENTERCebu Main: 4th floor Coast Pacific Downtown Center, Sanciangko St, Cebu City Tel #(032) 254-33- Manila Branch: 3rd floor JPD Bldg 1955, C M Recto corner N. Reyes St, Sampaloc, Manila Tel # (02) 736-MACHINE DESIGN - STRESSES & MACHIN...

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ALCORCON ENGINEERING REVIEW CENTER Cebu Main: 4th floor Coast Pacific Downtown Center, Sanciangko St, Cebu City Tel #(032) 254-33-84 Manila Branch: 3rd floor JPD Bldg 1955, C M Recto corner N. Reyes St, Sampaloc, Manila Tel # (02) 736-4438

MACHINE DESIGN - STRESSES & MACHINE ELEMENTS PROBLEM SET # 1 INSTRUCTION: Encircle the letter that corresponds to the correct answer of your choice. MULTIPLE CHOICE: 1.

Two cylinders rolling in the opposite direction has a speed ratio of 3. If the diameter of driver is 10 inches, find the center distance between cylinders. A. 15 in B. 10 in C. 25 in D. 20 in

2.

Two cylinders rolling in the same direction has a speed ratio of 2.5 and center distance of 50 cm. Find the diameters of the larger cylinder. A. 56.34 in B. 263/45 in C. 166.67 in D. 66.67 in

3.

Four cylinders rolling in opposite directions has a speed ratio of A:B:C:D = 5:3:1:4. If center distance between cylinder A and C is 70 inches, find the diameter of cylinder D. A. 18.75 in B. 26.34 in C. 12.45 in D. 16 .37 in

4.

A pulley has a tangential velocity of 75 fpm. If pulley diameter is 10 inches, find the speed of the speed. A. 24.34 rpm B. 28.65 rpm C. 34.22 rpm D. 32.34 rpm

5.

Shaft A with 12 inches diameter pulley running at 250 rpm is connected to shaft B by means of 26 inches diameter pulley. Another pulley on shaft B 16 inches diameter is connected to 10 inches diameter pulley on shaft C. Find the speed of shaft C. A. 184.61 rpm B. 284.56 rpm C. 173.45 rpm D. 197.44 rpm

6.

A steel tie rod on bridge must be withstand a pull of 6200 lbs. Find the diameter of the rod assuming a factor of safety of 4 and ultimate stress of 66,000 psi. A. 0.234 in B. 0.534 in C. 0.691 in D. 0.734 in

7.

If the ultimate shear strength of steel plate is 45,000 psi, what force is necessary to punch a 0.9 in diameter hole in a 0.5 in thick plate using a factor of safety of 3.5. A. 63,617 lbs B. 61,567 lbs C. 65,378 lbs D. 69,345 lbs

8.

A 2.5 in diameter by 1.8 in long journal bearing is to carry 5000 lb load at 320 rpm using SAE 40 lube oil at 200oF through a single hole at 30 psi. Compute the bearing pressure. A. 1111.11 psi B. 142.23 psi C. 123.34 psi D. 197.34 psi

9.

A journal bearing has 8 cm diameter and length to diameter ratio of 3. Find the projected area in mm2. A. 19,200 B. 20,009 C. 18,058 D. 17,017

10. A cable steel has a length of 100 m and stretch to 5 cm when the load is applied at both ends. If tensile stress is 50 psi, find the modulus of elasticity of the steel. A. 100,000 psi B. 120,000 psi C. 110,000 psi D. 130,000 psi 11. A shaft whose torque varies from 2200 to 6400 in-lb. It has a diameter of 1.25 inches and yield stress of 63,000 psi. Find the variable component stress. A. 6524.45 psi B. 4245.56 psi C. 5475.95 psi D. 7834.56 psi 12. How many 1/2-inch diameter hole that can be punch in one motion of a 1/8-inch-thick plate using a force of 50 tons. The ultimate shear stress is 52 ksi and factor of safety of 3. A. 7 B. 9 C. 8 D. 10 13. Determine the minimum diameter of a taper pin for use to fix a lever to a shaft, if it is to transmit a maximum torque of 750 in-lb. The shaft diameter is 1.5 inches and has a stress of 20,000 psi. A. 0.252 in B. 0.452 in C. 0.642 in D. 0.826 in

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14. A 19mm stud bolts is used to fastened on a 250 mm diameter cylinder head of diesel engine. If there are 10 stud bolts, determine the pressure inside the cylinder if bolt stress is 50 Mpa. A. 288.8 KPa B. 2888 KPa C. 3426 KPa D. 4828 Kpa 15. A column supports a compressive load of 250 KN. Determine the outside diameter of column if inside diameter is 185 mm and compressive stress of 50 Mpa. A. 200.62 mm B. 201.47 mm C. 216.42 mm D. 208.41 mm 16. A steel hollow tube is used to carry a tensile load of 500 KN at a stress of 140 Mpa. If outside diameter is 10 times the tube thickness of the tube. A. 11.24 mm B. 107 mm C. 20.64 mm D. 22.61 mm 17. A 20 mm diameter rivet is used to fastened two 25 mm thick plate. If the shearing stress of rivet is 80 Mpa, what tensile force applied each plate to shear the bolt? A. 26.35 KN B. 28.42 KN C. 30.41 KN D. 25.13 KN 18. Two 30 mm thick plate is fastened by two bolts, 25 mm in diameter. If the plate is subjected to 50 KN tension, find the bearing stress in bolts. A. 33333.33 KPa B. 4444.44 KPa C. 5555.55 KPa D. 555555 Kpa 19. What force is necessary to punch a 30 mm hole in 12.5 mm thick plate if ultimate shear stress is 410 Mpa? A. 480 KN B. 481 KN C. 482 KN D. 483 KN 20. A 2.5 inches shaft is subjected to 3 KN.m torque. Find the stress developed. A. 48.62 MPa B. 52.75 Mpa C. 59.67 MPa

D. 38.64 Mpa

21. A shaft when subjected to pure torsion developed a stress of 50 Mpa. If polar moment of inertia is 6.1359 x 10-7 m4, determine the maximum torque the shaft could handle. A. 1.23 KN.m B. 1.68 KN.m C. 1.84 KN.m D. 2.48 KN.m 22. A lever, secured to a 50 mm round shaft by a steel tapered pin (d = 10 mm), has a pull of 200 N at a radius of 800 mm. Find S, the working stress on the pin, in Mpa. Consider double shear on the pin. A. 41 B. 43 C. 46 D. 48 23. In a 2.0 m cantilevered I-beam, 2 Mton weight is applied at free end. If the allowable stress in beam is 110 Mpa, determine the section modulus. A. 18.54 in3 B. 21.77 in3 C. 26.83 in3 D. 24.28 in3 24. A 6 mm steel wire is 5 m long and stretches 8 mm under a given load. If modulus of elasticity is 200 Gpa, find the load applied. A. 7 KN B. 8 KN C. 9 KN D. 10 KN 25. A steel wire 10 m long, hanging vertically supports a tensile load of 2 KN. Neglecting the weight of wire, determine the required diameter if the stress is not to exceed 140 Mpa and the total elongation is not to exceed 5 mm. Assume E = 200 Gpa. A. 2 mm B. 3 mm C. 4 mm D. 5 mm 26. An iron rod 4 m long and 0.5 cm2 in cross section stretches 1 mm when a mass of 225 kg is hanged on it. Compute the modulus of elasticity of the iron. A. 176.58 GPa B. 169.81 Gpa C. 160.41 GPa D. 180.26 Gpa 27. A 20 m rod is stretches to a strain of 0.001. Determine the deflection of the rod. A. 20 mm B. 25 mm C. 30 mm

D. 35 mm

28. A rail having a coefficient of linear expansion of 11.6 x 10-6 m/m°C increases its length when heated from 70°F to 133°F. Determine the strain. A. 2.04 x 10-4 B. 6.05 x 10-4 C. 4.06 x 10-4 D. 2.77 x 10-4 29. What temperature will the rails just touched if steel railroad is 10 m long are laid with clearance of 3 mm at initial temperature of 15°C. Use k = 11.7 x 10-6 m/m°C. A. 35.64°C B. 40.56°C C. 45.64°C D. 50.64°C

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30. A hollow shaft has an inner diameter of 0.035 m and outer diameter of 0.086 m. Determine the polar moment of inertia of the hollow shaft. A. 4.512 x 10-6 m4 B. 5.222 x 10-6 m4 C. 6.52 x 10-6 m4 D. 7.125 x 10-6 m4 31. It is a problem of expansion and shrinkage of steel material so that the slightly smaller hole of a steel bushing of 1.999 diameter with the following process/materials/data to apply: Coefficient of expansion of carbon steel = 0.0000068 in/in-F. Temperature raised by gas heating = 24.5oF Cooling media to use dry ice with boiling point of -109.3oF (-78.5oC). Shrinkage rate below boiling point is 0.00073 in/in. Determine the final clearance between the expanded steel bushing hole against the shrinkage of the steel shaft. A. 0.000793 B. 0.000693 in C. 0.000750 in D. 0.000800 in 32. What modulus of elasticity in tension is required to obtain a unit deformation of 0.00105 m/m from a load producing a unit tensile stress of 44,000 psi? A. 42,300 x 106 psi B. 41,202 x 106 psi C. 43,101 x 106 psi D. 41,905 x 106 psi 33. If the weight of 6” diameter by 48” long SAE 1030 shafting is 174.5 kg, then what will be the weight of chromium SAE 51416 of same size? A. 305.5 lbs B. 426.4 lbs C. 384.6 lbs D. 465.1 lbs 34. Compute the maximum unit shear in a 3 inches diameter steel shafting that transmits 2400 in-lb of torque at 99 rpm. A. 452.71 psi B. 425.70 psi C. 386.90 psi D. 493.20 psi 35. If the ultimate shear stress of a 1/8 inch thick drawn steel plates is 35 ksi what force is required to punch a 1½ inch diameter hole? A. 10,011 lbs B. 22,322 lbs C. 11 Mtons D. 20620 lbs 36. The shaft whose torque varies from 2000 to 6000 in-lbs has 1 ½ inch in diameter and 60,000 psi yield strength. Compute for the shaft mean average stress. A. 6036 psi B. 6810 psi C. 5162 psi D. 5550 psi 37. A link has a load factor of 0.80 the surface factor of 0.80. The surface factor is 0.92 and the endurance strength is 28000 psi. Compute the alternating stress of the link if it is subjected to a reversing load. Assume a factor of safety of 3. A. 8150 B. 10920 C. 9,333 D. 7260 38. The shaft is subjected to a steady load of 36,000 in-lb at a shear stress of 10,000 psi. Compute the diameter of the said shaft in inches. A. 1 7/8 B. 2 ¼ C. 3 D. 2 ¾ 39. A shear pin is to be shear at 15 hp and 1000 rpm. The pin attaches a hub to a shaft 1.5 inches in diameter and ultimate shearing stress of 50,000 psi. Find the diameter of the pin. A. 1/8 in B. ¼ in C. ¾ in D. 1 in 40. A steel 0.5 inch x 1 inch steel 200 ft long is subjected to a 5000 lbs tensile load. Find the deformation along its width if poison’s ratio is 0.25. A. 0.000007 in B. 0.0000417 in C. 0.000015 in D. 0.000067 in 41. A steel rod is stretched between two rigid walls and carries a tensile load of 5000 N at 20oC. If the allowable stress is not to exceed 130 MN/m2 at -20oC, what is the minimum diameter of the rod? Assume k = 11.7 µm/(m-oC); E = 200 Gpa A. 10.22 mm B. 11.22 mm C. 12.22 mm D. 13.22 mm

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ANSWER KEY 1. D

2. C

3. A

4. B

5. A

6. C

7. A

8. A

9. A

10. A

11. C

12. B

13. A

14. B

15. B

16. A

17. D

18. A

19. D

20. C

21. A

22. A

23. B

24. C

25. D

26. A

27. A

28. C

29. B

30. B

31. A

32. D

33. C

34. A

35. D

36. A

37. C

38. D

39. B

40. B

41. D

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