图示半径为R,质量为m1的均质滑轮上,作用一常力偶M,提升一质量为m2的重物,则重物上升高度h的过程中,力偶M的功为_______
A: 选项D
B: 选项B
C: 选项A
D: 选项C
A: 选项D
B: 选项B
C: 选项A
D: 选项C
举一反三
- 均质圆盘C质量为m，半径为r，在半径为R的圆弧形轨道上纯滚动，轮心C点速度v为常数；则在图示瞬时圆盘对C轴的动量矩大小为（ ）<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201805/4f2a21f5641e442aa7af905c5ad08bd6.png" /><img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201805/1ed8790882b54d5cb39ed37af07e4f96.png" /> A: 选项A B: 选项D C: 选项B D: 选项C
- 图示半径为R,质量为m1的均质滑轮上,作用一常力偶M,提升一质量为m2的重物,则重物上升高度h的过程中,力偶M的功为_______[img=166x228]17d60528040b5b9.png[/img][img=358x102]17d60528130311b.png[/img] A: 选项D B: 选项B C: 选项A D: 选项C
- 在均匀电场中，作一半径为R的半球面，使半球面的轴与场强E的方向平行，则通过这一半球面的电通量为 A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201805/bf341a312be54f3c99c3472135e65b4d.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201805/75062c5d50c24d6684010689732915ac.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201805/47e2f56b1f234526a7582ca537740bcc.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201805/5284cd2d979041baaed0b04028cfb72b.png" />
- 略去质量的弹簧原长为2L，刚度为k，两端固定并处于水平位置，在弹簧中点挂一重物，则重物下降x路程中弹性力所作的功为________。<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/a23821c4ff754f00aa2f3bdcbff7740f.png" /> A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/484da0f3795d4eb39a41a86f9515c4d6.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/a11e055bb31c450c8a9359b0339db3bf.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/6b19f1dc9b8b40ce92f397749e440b2c.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201812/a1a5d63b6d424b68a3e81a565a849360.png" />
- 图示曲柄连杆机构，已知曲柄OA长L，重量不计，连杆AB长2L，重P，受矩为M的力偶和水平力Ｆ的作用，在图示位置平衡。若用虚位移原理求解，则必要的虚位移之间的关系为___________，力F的大小为_____________________。<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/be06434307bd424abfc4ebfe02661f7a.png" /> A: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/b8e7b964d1c84aeca7b22ddef4de87a2.png" />;<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/a584946cde17410c945d6611ff2113b5.png" /> B: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/1aaef24e28ee477ab25dae0a400bf23f.png" />;<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/f3b395453e1d48bdadff2e37dfbbb626.png" /> C: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/be37912822f0451bb15639b7fa0589f1.png" />;<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/6d1112b5c1b4446b93578138388ed79f.png" /> D: <img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/89b7bcef6b51410cb624a654747d56ee.png" />;<img src="http://image.zhihuishu.com/zhs/onlineexam/ueditor/201901/0e2b78f437914a1eb8327d13185eaedf.png" />