ANSWERS TO PROBLEMS 



1. 17.7 lb./in. 2 . 2. 3.1 lb./in. 2 . 3. s = .0018. 4. 5.4 in. 5. .0000104. 



6. s = .002122, 12.73 in. 7. 16,500,000 lb./in. 2 , approximately. 



8. .0055 in., approximately, s = .00002546. 9. 31,024 Ib. 



10. .0737. 11. .0057 in. 12. 1005 Ib. 13. .24 in. square. 



H 15. 99 tons. 16. 20.0086ft. 17. 1890 lb./in. 2 . 



18. .16 in. 19. 13,320 lb./in. 2 . 20. 1.7, approximately. 



21. IS\. 22. .84 in. in diameter. 25. 320 lb./in. 2 , 19 19.8', 109 19.8'. 



26. p' - 2000 lb./in. 2 , q* = 3460 lb./in. 2 , q' max = 4000 lb./in. 2 . 



27. 10,000 lb./in. 2 . 28. 64,240 Ib. 



29. L>3,868 Ib. direct stress, 77,748 Ib. shear. 30. 5656 lb./in. 2 . 



31. With a factor of safety of 5, d = 1.21 in. 32. m = 5. 



33 p, = 556 lb./in. 2 for m = 3J. 34. p e = 12,646 lb./in. 2 for m = 3|. 



36. ' 37. - 39. 116,600ft. Ib. 



64 



40. 942,.-XX) ft. Ib. 41. J/ t : .17, = 261.3 : 149.3. 42. , , . 



1 6 24 32 



43. N, : N 3 = 5:2. 45. (3 A 2 + ft 2 ). 46. ^ (6A 3 - 6'A' 3 ). 



48 



48. / 55. Zero at center, 1500 Ib. at ends. 



56. 4250 Ib. and 4750 Ib. at ends, 2750 Ib. and 1750 Ib. between loads. 



57. At renter; 1837.5 ft. Ib. 58. 408 lb./in. 2 . 



59. 11,603 lb./in. 2 . 63. S = 66.46 in.*. 64. In the ratio 1 : 96. 



P PZ 3 



76. y = (2l*-3J2z + as), D = 



SEI 



78 y = ^ ;-(J 3 -2te 2 + x*), D=- 



Jl#/ v 384^7 



79. y = -^<*-4fl* + 8*),I> = -^-. 

 24/ V 8^7 



80. 7>=.07in. 81. D=. 067 in. 83. D = 



84. It 85. D = .061 in. for E c = 2,000,000 lb./in. 2 . 



90. .V, = J/ 6 = 0,3/ 2 = M B = - ^wl^M 3 = M 4 =-wl 2 , F l = F & = $% wl, 



92. M' :;'.7 in. Ib. 94. h = 7.86 in. 101. 350 tons. 



102. f; in. square. 103. 5.82 in. 104. 6J in. wide for angles | in. thick. 



105. Rankine 616 tons. Johnson 627 tons. 106. Rankine 268 tons, Johnson 267 tons. 

 107. Assume various lengths for the column. 108. 127 tons. 



109. 15+. 110. 2 1 in. square. 



113 (7 = 11,490,000 lb./in.*. 114. M= 43.24 in. Ib. 



307 



