如图[tex=2.857x1.143]UDtihf+xJ3VwTZELJnnb7A==[/tex]所示, 用绳索匀速起吊一重[tex=3.714x1.0]AIPY0+mZfuL2bOsVVMm5p3Pj1KEv9OkMjfMBf1+1P/0=[/tex] 的重物, 已知 [tex=2.857x1.071]lBO+mfYgZ1CFKs9S0+C8qHEp2KghVdgTSaiJwK7Qt2A=[/tex], 绳索的横截面面积[tex=5.643x1.214]Hik7DN9xlmIKR3QF/GVmXnwlY9SzrH8bRDFMowPk2yw=[/tex], 许用应力[tex=5.0x1.357]MPYM9NO5Jj9SbGL7Wdhtd9X9lzWmkLBmijZv89erzNQ=[/tex] 。试校核绳索强度。[img=607x416]17cf0b081a15a44.png[/img]
举一反三
- set1 = {x for x in range(10) if x%2!=0} print(set1) 以上代码的运行结果为? A: {1, 3, 5, 7, 9} B: {1, 3, 5, 7} C: {3, 5, 7, 9} D: {3, 5, 7}
- set1 = {x for x in range(10) if x%2!=0} set1.remove(1) print(set1) 以上代码的运行结果为? A: {1, 3, 5, 7, 9} B: {1, 3, 5, 7} C: {3, 5, 7, 9} D: {3, 5, 7}
- >>>x= [10, 6, 0, 1, 7, 4, 3, 2, 8, 5, 9]>>>print(x.sort()) 语句运行结果正确的是( )。 A: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10] B: [10, 6, 0, 1, 7, 4, 3, 2, 8, 5, 9] C: [10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0] D: ['2', '4', '0', '6', '10', '7', '8', '3', '9', '1', '5']
- set1 = {x for x in range(10)} print(set1) 以上代码的运行结果为? A: {0, 1, 2, 3, 4, 5, 6, 7, 8, 9} B: {0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10} C: {1, 2, 3, 4, 5, 6, 7, 8, 9} D: {1, 2, 3, 4, 5, 6, 7, 8, 9,10}
- 用绳索吊运一重 [tex=3.786x1.0]6ORF66w6O1F+phk3doJS+Q==[/tex] 的重物,如图所示。设绳索的横截面面积 [tex=5.286x1.429]M/kgrmZHS8WIw1UAXDa3TK/izG5tsfkEZee6PJjU+3g=[/tex]许用应力 [tex=5.357x1.357]P7zL+dpiV8bC9uKslCIT84dbsJynnStHybjyBJEWQoA=[/tex] 试问:(1)当 [tex=2.857x1.071]lBO+mfYgZ1CFKs9S0+C8qHEp2KghVdgTSaiJwK7Qt2A=[/tex]时,绳索强度是否够用?(2)如改为[tex=3.143x1.286]z7opkeLRldjTaMX1PsKn0BT91C/ihxCB0s3i/3GVGiI=[/tex]再校核绳索的强度。[img=249x468]179c09784c83ea8.png[/img]