That is mg-qE= 12(mg+qE), so e = mg3q.
(2) Work done by gravity: WG = mgl (cos 30-cos 60)-mgl cos 60 = (32-1) mgl.
Electrostatic force does work: we = qel (cos 30-cos 60)+qelcos60 = 36mgl.
(3) According to the law of conservation of energy, 12? 2mv2=Wg+We=(233- 1)mgl，
Holding speed: v=△Ekm=(233? 1) general ledger.
Answer: (1) The field strength e of uniform electric field is mg. I've praised it all. I've stepped on it. What's your comment on this answer? Put away the comments and recommend lawyer services: If your problem has not been solved, please describe your problem in detail and provide free professional consultation through Baidu Legal Pro. Other similar questions 2011-08-11. As shown in the figure, the two balls A and B have the mass of m and are fixed in a slender lamp with the length l =1m. As shown in the figure, 820 17-09-25 can bypass the O point, and there are two balls A and B fixed at both ends of a long straight rod, the mass of both balls is m, ignoring the radii of the two balls, and the length of the rod is. 1. 520 1 1-07-29, as shown in the figure, is a polished rod with length L, and balls A and B are fixed at both ends, where the mass of A is m and the mass of ball B is 2m172011-08. As shown in the figure, the lengths of OA and OB are 2720 12-06-02 respectively. Two balls A and B, both of which are of mass M, are connected by a light bar with a length of 3L, which can be wound around 420 13-09-09, and the distance from ball A is 2L, as shown in the figure. Connect a polished rod with length L between two balls A and B with mass m and 2m respectively. These two balls can be wound around the rod 72014-11-24. As shown in the figure, there are two balls A and B with mass m on a polished rod, and the polished rod can freely rotate around point O in the vertical plane, OA = AB = L. First, pull the rod 520 17-09-658. As shown in the figure, one end of a lamp pole with a length of 6L is connected with a ball with a mass of m, and the other end is fixed at the hinge O (the lamp pole can be wound three times). [{ ' URL ':'/d 0 1373 f 082025 AAF 5 1 1aa 256 e 9 edab 64034 f 1a 07？ 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 ':' '，}])； 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? Is Huaqiang North's second-hand mobile phone reliable? 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 = 17 193 14480；