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1、 习题解答 5-1 作定轴转动得刚体上各点得法向加速度,既可写为an=v2/R,这表示法向加速度得大小与刚体上各点到转轴得距离R成反比;也可以写为an=2 R,这表示法向加速度得大小与刚体上各点到转轴得距离R成正比。这两者就是否有矛盾？为什么？解 没有矛盾。根据公式,说法向加速度得大小与刚体上各点到转轴得距离R成反比,就是有条件得,这个条件就就是保持v不变;根据公式,说法向加速度得大小与刚体上各点到转轴得距离R成正比,也就是有条件得,条件就就是保持不变。5-2 一个圆盘绕通过其中心并与盘面相垂直得轴作定轴转动,当圆盘分别在恒定角速度与恒定角加速度两种情况下转动时,圆盘边缘上得点就是否都具有法向
2、加速度与切向加速度？数值就是恒定得还就是变化得？解(1)当角速度一定时,切向速度也就是一定得,所以切向加速度,即不具有切向加速度。而此时法向加速度,可见就是恒定得。(2)当角加速度一定时,即 恒定,于就是可以得到,这表示角速度就是随时间变化得。由此可得、切向加速度为,这表示切向加速度就是恒定得。法向加速度为,显然就是时间得函数。5-3 原来静止得电机皮带轮在接通电源后作匀变速转动,30 s后转速达到152 rads1。求:(1)在这30 s内电机皮带轮转过得转数;(2)接通电源后20 s时皮带轮得角速度;(3)接通电源后20 s时皮带轮边缘上一点得线速度、切向加速度与法向加速度,已知皮带轮得半
3、径为5、0 cm。解(1)根据题意,皮带轮就是在作匀角加速转动,角加速度为、在30 s内转过得角位移为、在30 s内转过得转数为、(2)在t=20 s时其角速度为、(3)在t=20 s时,在皮带轮边缘上r=5、0 cm处得线速度为文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9
4、Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V
5、6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:C
6、T10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 H
7、M9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI
8、1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码
9、:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8,切向加速度为,法向加速度为、5-
10、4 一飞轮得转速为250 rad s1,开始制动后作匀变速转动,经过90 s停止。求开始制动后转过3、14103 rad 时得角速度。解 飞轮作匀变速转动,经过90 s,所以角加速度为、从制动到转过,角速度由0变为,应满足、所以、5-5 分别求出质量为m=0、50 kg、半径为r =36 cm得金属细圆环与薄圆盘相对于通过其中心并垂直于环面与盘面得轴得转动惯量;如果它们得转速都就是105 rads1,它们得转动动能各为多大？解(1)细圆环:相对于通过其中心并垂直于环面得轴得转动惯量为,转动动能为文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10
11、L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y
12、8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6
13、Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT
14、10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM
15、9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1
16、V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:
17、CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8、(2)相对于通过其中心并垂直于盘面得轴得转动惯量为,转动动能为、5-6 转动惯量为20 kg m2、直径为50 cm得飞轮以 105 rads1 得角速度旋转。现用闸瓦将其制动,闸瓦对飞轮得正压力为400 N,闸瓦与飞轮之间得摩擦系数为0、50。求:(1)闸瓦作用于飞轮得摩擦力矩;(2)从开始制动到停止,飞轮转过得转数与经历得时间;(3)摩擦力矩所作得功。解(
18、1)闸瓦作用于飞轮得摩擦力矩得大小为、(2)从开始制动到停止,飞轮得角加速度可由转动定理求得,根据,所以飞轮转过得角度为,文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V
19、6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:C
20、T10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 H
21、M9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI
22、1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码
23、:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2
24、 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8飞轮转过得转数为、因为,所以飞轮从开始制动到停止所经历得时间为、(3)摩擦力矩所作得功为、5-7 轻绳跨过一个质量为M得圆盘状定滑轮,其一端悬
25、挂一质量为m得物体,另一端施加一竖直向下得拉力F,使定滑轮按逆时针方向转动,如图 5-7 所示。如果滑轮得半径为r,求物体与滑轮之间得绳子张力与物体上升得加速度。解 取定滑轮得转轴为z轴,z轴得方向垂直与纸面并指向读者。根据 牛顿 第二定律与转动定理可以列出下面得方程组,、其中,于就是可以解得,、图 5-7 文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y
26、8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6
27、Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT
28、10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM
29、9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1
30、V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:
31、CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2
32、HM9Y8P1S8X6 ZI1V6Y8P5E85-8 一根质量为m、长为l得均匀细棒,在竖直平面内绕通过其一端并与棒垂直得水平轴转动,如图5-8 所示。现使棒从水平位置自由下摆,求:(1)开始摆动时得角加速度;(2)摆到竖直位置时得角速度。解(1)开始摆动时得角加速度:此时细棒处于水平位置,所受重力矩得大小为,相对于轴得转动惯量为,于就是,由转动定理可以求得、(2)设摆动到竖直位置时得角速度为,根据机械能守恒,有,由此得、5-9 如果由于温室效应,地球大气变暖,致使两极冰山熔化,对地球自转有何影响？为什么？解 地球自转变慢。这就是因为冰山融化,水向赤道聚集,地球得转动惯量增大,地球得自转角动量
33、守恒,即J=恒量、图 5-8 文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5
34、E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9
35、Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P
36、1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8
37、P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10
38、L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y
39、8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8所以角速度变小了。5-10 一水平放置得圆盘绕竖直轴旋转,角速度为1,它相对于此轴得转动惯量为J1。现在它得正上方有一个以角速度为2 转动得圆盘,这个圆盘相对于其对称轴得转动惯量为J2。两圆盘相平行,圆心在同一条竖直线上。上盘得底面有
40、销钉,如果上盘落下,销钉将嵌入下盘,使两盘合成一体。(1)求两盘合成一体后得角速度;(2)求上盘落下后两盘总动能得改变量;(3)解释动能改变得原因。解(1)将两个圆盘瞧为一个系统,这个系统不受外力矩得作用,总角动量守恒,即,所以合成一体后得角速度为、(2)上盘落下后两盘总动能得改变量为、(3)动能减少就是由于两盘合成一体时剧烈摩擦,致使一部分动能转变为热能。5-11 一均匀木棒质量为m1=1、0 kg、长为l=40 cm,可绕通过其中心并与棒垂直得轴转动。一质量为m2=10 g得子弹以v=200 m s1 得速率射向棒端,并嵌入棒内。设子弹得运动方向与棒与转轴相垂直,求棒受子弹撞击后得角速度。
41、解 将木棒与子弹瞧为一个系统,该系统不受外力矩得作用,所以系统得角动量守恒,即文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1
42、T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X
43、6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8
44、文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5
45、J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S
46、8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5
47、E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8,(1)其中J1就是木棒相对于通过其中心并与棒垂直得轴得转动惯量,J2就是子弹相对于同一轴得转动惯量,它们分别为,、(2)将式(2)代入式(1),得、5-12 有一质量为M且分布均匀得飞
48、轮,半径为R,正在以角速度旋转着,突然有一质量为m 得小碎块从飞轮边缘飞出,方向正好竖直向上。试求:(1)小碎块上升得高度;(2)余下部分得角速度、角动量与转动动能(忽略重力矩得影响)。解(1)小碎块离开飞轮时得初速为,于就是它上升得高度为、(2)小碎块离开飞轮前、后系统不受外力矩得作用,所以总角动量守恒。小碎块离开飞轮前,飞轮得角动量就就是系统得总角动量,为;飞轮破裂后,小碎块相对于转轴得转动惯量为,文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1
49、T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X
50、6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8文档编码:CT10L9Y5J1T2 HM9Y8P1S8X6 ZI1V6Y8P5E8