(1) Let the velocity of ball A at the bottom be v. From the release to the lowest position, the mechanical energy of the system composed of ball A and ball B is conserved, and the decrease of gravitational potential energy is equal to the increase of kinetic energy of the system: mAgl? mBgl = 12 MAV 2+ 12 mbv 2…①

Solution: V = 27GL

Suppose that in this process, the rod does work w on the B ball, and the kinetic energy theorem is applied to the B ball in this weighing: w? mBgl = 12 mbv2……②

② The result is: w = 247mgl.

(2) When the OA lever rotates by an angle of α, the speed of ball A is V', and the speed of ball B is V'.

The conservation of mechanical energy in a and b ball systems is determined by the law of conservation of mechanical energy: mAglsinα? mBgl( 1？ cosα)= 12 MAV′2+ 12 mbv′2…③

Substitution data collation: V ′ = 27GL [5Sin (α+β)? 3]

Where tanβ= 34°, β = 37, α = 53, and V' has the maximum value.

Therefore, the speed of ball A is the maximum when it turns α = 53 from the starting position: VM ′ = 47GL.

(3) Make a state diagram of the ball A just touching the thin line, as shown in the figure.

Let OD be perpendicular to o ′ b ′. According to the geometric relationship, OD = 22l and OO'= 2l, so θ = γ = 60.

The falling height of the ball ha: ha = lsinγ = 32l...④

Rise height of block c HB: HB = 2LSinθ+22L? l=6+2？ 22l…⑤

The mechanical energy conservation of the system composed of A and C in this process: mAghA=mCghC…⑥.

Substituting the data, I found that MC = 436+2? 2m

Answer: (1) The work done by the lever to the ball B from the release to the lowest position is 24mgl7.

(2) The velocity of ball A is the maximum at an angle of 53 with the horizontal plane, and the maximum value is 4gl7.

(3) The mass of block C is 436+, which is praised and trampled. What is your evaluation of this answer? Put away comments//high quality or satisfaction or special types or recommended answers dottimewindow.iperformance & window.iperformance.mark ('c _ best',+newdate); Lawyer recommendation service: If your problem has not been solved, please describe your problem in detail and provide free professional consultation through Baidu Law Professional Edition. Other similar problems 2016-12-01. As shown in the figure, balls A and B with equal mass are fixed at the midpoint and endpoint of the light bar respectively. When the rod rotates around the O point at a uniform speed on a smooth horizontal plane, find the rod 2820 17-09-25. As shown in the figure, two balls A and B are fixed at both ends of a long straight rod, the mass of both balls is m, and the length of the rod is. First, 520 12-03-25 is a rigid polished rod with a length of 2L, and two balls are fixed at both ends. Ball A has a mass of m, ball B has a mass of m, and the water passing through the midpoint o of the rod is 520 14-05-3 1, as shown in the figure. Two balls A and B are fixed at two ends of a rigid polished rod respectively, and the centers of the two balls are. As shown in the figure, the mass of the two balls is mA=520 16-05-09. Two balls A and B are fixed at both ends of a thin rod, and a smooth horizontal shaft is installed at the O point on the rod. It is known that the mass of both balls is m, as shown in the figure, the mass of ball A is also m.. It moves around the O point at the other end of the rod in a vertical plane together with the rod. For example, 32016-12-01As shown in the figure, two balls A and B (which can be regarded as particles) with mass of mA and mB are fixed at both ends of a polished rod respectively. Put them in the right-angle smooth groove 220 16-06. & gt recommended for you: F.context('cmsRight', [{'URL':'/d01373f082025aaf511aa256e9edab64034f1a07? x-BCE-process = image % 2f resize % 2Cm _ lfit % 2Cw _ 450% 2Ch _ 600% 2c limit _ 1% 2f quality % 2Cq _ 85% 2f format % 2Cf _ auto '，' contractId':'A24KA00562 '，}，{ ' URL ':/s？ word = % E6 % AC % A7 % E6 % B4 % B2 % E6 % 9D % AF & sa = searchpromo _ ozb _ zhidao _ tuijian '，' src ':'/3 BF 33 a 87 e 950352 AAF 5 df 4954 143 fbf2b 2 1 18 b6b？ x-BCE-process = image % 2f resize % 2Cm _ lfit % 2Cw _ 450% 2Ch _ 600% 2c limit _ 1% 2f quality % 2Cq _ 85% 2f format % 2Cf _ auto '，' contractId ':' '，}])； Is Huaqiang North's second-hand mobile phone reliable? Why is the cost of cancer treatment getting higher and higher? What impact will the "network toilet" have? The price of electric cars has dropped many times. Is the quality guaranteed? I recommend f.context ('recbrand', [{"img": "\/86D6277F9E2F07083523F69DFB 24B 899A901F20d? x-BCE-process = image % 2f resize % 2Cm _ lfit % 2Cw _ 450% 2Ch _ 600% 2c limit _ 1% 2f quality % 2Cq _ 85% 2f format % 2Cf _ auto "，" url":"/hm.js？ 6859 ce 5a af 00 FB 00387 e 6434 E4 FCC 925 "； var s = document . getelementsbytagname(" script ")[0]； s.parentNode.insertBefore(hm，s)； })(); window . TT = 1720 129360；