用螺旋测微器测量其直径如图乙所示,由图可知其直径D =____mm;( )
劲度系数k(N/m) | 钢丝的直径 D(mm) | D-1(mm-1) | D2(mm2) | D3(mm3) | D4(mm4) | |
1 | 132 | 0.9 | 1.11 | 0.81 | 0.73 | 0.66 |
2 | 414 | 1.2 | 0.83 | 1.44 | 1.73 | 2.07 |
3 | 1 012 | 1.5 | 0.67 | 2.25 | 3.38 | 5.06 |
钩码数 | 1 | 2 | 3 | 4 |
LA/cm | 15.71 | 19.71 | 23.66 | 27.76 |
LB/cm | 29.96 | 35.76 | 41.51 | 47.36 |