[img=391x205]1799ce4241a262b.png[/img]试求题图[tex=3.357x1.286]9pzXvDs9cKwc2gNcpkNg0w==[/tex]所示两平面图形的形心位置,尺寸单位为[tex=1.786x0.786]03tWdMu1dxxloqOH8i8LVA==[/tex]。
[img=190x211]1799ce4c85c5cfe.png[/img]解 首先确定题图 ([tex=0.571x0.786]c59+3vo0/Vn/FvNRhDRu5g==[/tex])中的扇形面积的形心位置,如图所示。在图中,面积元[tex=4.643x1.214]shLbIcP4TGOnceQ72hwCiW6YRyKF1TsieEDiDxVViRk=[/tex]它的形心坐标[tex=9.286x1.214]Cx/lIioOOZIQkPYKFbmPlG/PsWuzfOXRLXusc6XgGnPo9eGZDUiFebXOXFZgEG8d[/tex]所以,扇形面积的形心位置为[tex=28.429x7.0]Lappu9NSIIGARJyf+ZCjuGkVYSOkyl5R6k50qHdJY8PA1i3JSBXvOn/Cjupjnwgea7NqvTGsgH87bgMUc8d/tTd1uymYyNN7Jhxzvhk7b9zjPLPu86TRL0TddXCqXTC6wP+X/P2VYn8Nb6o9/LL/BiysO77Ewka8QIDFW5X2bCgLOrMb4wHEeT8eIDah90+P/KTNzHL3+atUM/d5g/7fkc2m8IP0HLc8B1YvKh5LPhefdU7UHVu6qn+UbQdTKP8WbODpBcWn1VENauSWT0XIy0cUUdqb3RyqhKIIkaqO6FEEe2AKtfGLqj9qkvBXkT5PUZfY2GOigiVUVq3hwdPtRQh0p+c/LuAQG1i7Q716E0xyk+TZYo5FVzVMmufZV3p/xAYQYtZgcgGkEJu47Ph1W0i8b3YGKPAv82b1KPTGN8ycI9UROqDl18HFzfNzcCJieTSDEkZdlpFJMNTactkOlO86HlKG3heUgMu91vSdkRUTpgIH1m/Hvjxv7rrsLiUnfKt22DBE3Zev7pAbQIRcXZls8v9uNErj3s/8vlsXj+XQvE0QdG0A9n/mgNTvxG12Qw/NShdHrwVrosEcPtMj5mhocP3zHuqpt+iItn+80ODvZXSew26qh1/JXTXpeC5SpgBdVGJxyO83W9mbtWe6qwxjgn089xUoqQGwT3VHVRr/KrzfnhYQjO45jzu9RV5wPwKft8aHuazX5/ttmkkUCwYKkqxwSURW51/BNNVHBb0=[/tex]再求题图([tex=0.571x0.786]c59+3vo0/Vn/FvNRhDRu5g==[/tex])所示阴影部分面积的形心位置:[tex=20.143x12.214]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[/tex]最后，求图所示阴影部分面积的形心位置:[tex=19.929x9.214]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[/tex]
举一反三
- [img=201x218]1799ce0e232d1fe.png[/img]试求题图所示两平面图形形心 [tex=0.714x1.0]YiLkHgl7MlxE+QjUplQUKA==[/tex]的位置,尺寸单位为 [tex=1.786x0.786]5p2rvkFvSUOnrQaoKDGvuA==[/tex] 。
- [img=168x219]1799cde3e407b22.png[/img]试求题图所示两平面图形形心[tex=0.714x1.0]YiLkHgl7MlxE+QjUplQUKA==[/tex] 的位置。图中尺寸单位为 mm。
- 纸片琼脂扩散法的各纸片中心相距是 未知类型：{'options': ['3[tex=1.786x0.786]03tWdMu1dxxloqOH8i8LVA==[/tex]', '4[tex=1.786x0.786]03tWdMu1dxxloqOH8i8LVA==[/tex]', '8[tex=1.786x0.786]03tWdMu1dxxloqOH8i8LVA==[/tex]', '>24[tex=1.786x0.786]03tWdMu1dxxloqOH8i8LVA==[/tex]', '>15[tex=1.786x0.786]03tWdMu1dxxloqOH8i8LVA==[/tex]'], 'type': 102}
- 设随机变量X的密度函数为[img=572x74]1791bc8f97085d2.jpg[/img]试求：（1）常数A；（2）[tex=6.714x1.357]AyFmD19eLybEpNdIrC346g==[/tex]
- 题[tex=2.143x1.286]cGrgtLI6TVXwCqa1Kpqbmg==[/tex]图[tex=3.357x1.286]9pzXvDs9cKwc2gNcpkNg0w==[/tex]所示电路中开关[tex=0.643x1.0]fYkALuFzYlFm0R716i1EGA==[/tex]在[tex=1.643x1.0]e6RhHIicI4xKNcYb53RxjQ==[/tex]时动作,试求电路在[tex=1.643x1.0]dg2Z5h0aD5IoWZq7/wtZbg==[/tex].时刻电压、电流的初始值。[img=539x226]179a6240c267793.png[/img]
内容
- 0
求题图所示图形对形心轴[tex=0.5x0.786]C7x+w8+jOPZzxFrGGne6Dw==[/tex] 的惯性矩。[img=222x271]179c6f1812434ec.png[/img]
- 1
求题图所示图形对形心轴[tex=0.5x0.786]C7x+w8+jOPZzxFrGGne6Dw==[/tex] 的惯性矩。[img=192x244]179c6fc47715c93.png[/img]
- 2
求题图所示图形对形心轴[tex=0.5x0.786]C7x+w8+jOPZzxFrGGne6Dw==[/tex] 的惯性矩。[img=215x261]179c6feefdeeabf.png[/img]
- 3
求题图所示图形对形心轴[tex=0.5x0.786]C7x+w8+jOPZzxFrGGne6Dw==[/tex] 的惯性矩。[img=184x268]179c6f2b904200b.png[/img]
- 4
电路如题图所示，输入为单位阶跃电流，已知 [tex=5.286x1.5]Plaj8XfmOUk7nfWelyhK/cMav3I9JS7uvBfBhS5GEC4MvPlAhCJPMiwdjDrBa8xh[/tex], [tex=5.143x1.5]0aRp5BilIB097CIDVFsV8WApWVCsinZUXoA0Bsh5vkz0R/8Dy2+UkDfmLWirSsng[/tex],试求电流[tex=0.857x1.214]KXScbyQu6GlmW314c6CP5Q==[/tex]。[img=379x219]179a33360a9400b.png[/img]